Construction Research Congress 2012: Construction Challenges in a Flat World

Although international construction projects offer new markets for construction services, there are still many challenges to moving into international markets. Contractors should be aware that though the international contracts they will sign may be similar to their own local contracts, they will still include some major additional/modified clauses that address international issues. Because disputes in construction projects are inevitable, one of the very critical contract clauses in an international contract is the dispute resolution clause. The objectives of this paper are to use the Delphi method to identify factors that have an effect on the choice of dispute resolution methods (DRM) in international construction contracts and to recommend specific DRM(s) to contractors based in English-speaking countries who operate in the Middle East or Asia. A panel of 11 international DRM experts participated in this study. Although all experts agreed that culture affects the choice of DRMs in international contracts, the most recommended DRMs to use in both cultures were arbitration followed by negotiations then mediation. The least recommended DRM in the Middle East was summary jury trial and in Asia was litigation. This study can be developed further by conducting interviews with the experts participating in the study to investigate why they chose similar DRMs for both cultures. More culture clusters can be included in the study to compare the variability in the results between cultures.

One of the main characteristics of construction projects in general is that they are subject to a wide range of risks causing delays beyond the planned completion dates. Due to the current unrest in the Middle East and North Africa, it is expected that the World Bank will fund many projects in the region to restore and build the affected and aged infrastructure systems. Under the current circumstances, these projects could be subject to delays. World Bank projects are managed through the Standard Bidding Documents for Procurement of Works (SBDW). The Conditions of Contract included in the SBDW (i.e. WB Contract) are based extensively on the Conditions of Contract for Construction published by the International Federation of Consulting Engineers (FIDIC). Since the WB Contract and the FIDIC have their own procedures that cover the submission of schedules (programmes, the term used in the WB Contract and the FIDIC), updating programmes and submission of claims for extension of time; some delay analysis techniques would fit to be applied to such contracts whereas other would not. Under these interrelated conditions, it is crucial for U.S contractors to utilize the appropriate delay analysis techniques that will enable them to study and assess the associated impact to the project schedules, and consequently submit well substantiated claims for extension of time. This paper uses a three-step methodology to present administration guidelines for appropriately applying the different delay analysis techniques to the World Bank funded projects.

The traditional project delivery method known as design-bid-build (DBB) has been known to give rise to adversarial relationships amongst and between project participants, and, as a result, litigation amongst and between such parties. It has been suggested that the design/build (DB) project delivery method has reduced the number of claims from the contractor to the owner since the designer is now a member of the contractor's project team. It is also suggested that the number of claims from the owner to the design-builder has been increased as a result of owner's dissatisfaction with the actual performance of the project. This research conducts a literature review and interviews with experienced project participants to gather information on DBB and DB with respect to claims. The key categories of claims and the underlying influential factors leading to those claims are identified. Qualitative data analysis is performed to determine how the DB approach has affected the typical influential factors leading to claims under the DBB model. This paper presents the result of the data analysis both in a framework and textual format.

Solar highway projects are to use highway right-of-way to generate renewable energy for highway electricity use. Although the concept is simple, the delivery of a solar highway project involves complicated partnerships among the public agency, utility company, investors, and all other contractors. Under these partnerships, contractual agreements and financing mechanisms such as power purchase agreement, tax credit pass-through, and renewable energy credits should be established to streamline the delivery system of solar highway projects. With an increasing interest but very limited experience in the US, state highway agencies desire to enhance their capacity to develop renewable energy projects at the lowest cost and risk. This paper presents three solar highway projects completed and under development in the state of Oregon to demonstrate the concept and key features for delivering successful solar highway projects. A general project delivery system is proposed based on the analysis of project partnership structure, project financing mechanisms and project delivery process. Critical success factors are identified to ensure a successful delivery, including political support, public-private partnership, public communication, and alignment with the agency's long-term missions.

State Highway Agencies have started to utilize price-time bi-parameter bidding (A+B bidding) in order to accelerate projects by incorporating construction time in the bidding competition. Since this method is based on the principle of cost reimbursement to the contractor for contract time reduction, the owner has to calculate unit time value (UTV) before letting projects. Unlike most studies performed in this area that have focused on optimizing the incentive/disincentive (I/D) rates with respect to road user costs and added construction cost, this study investigates how different UTVs can impact the competitiveness of contractors in A+B bidding. By evaluating the optimal strategies of multiple contractors participating in an A+B bidding competition, new criteria are developed to determine the amount of UTV and I/D. Finally, the paper concludes with some discussions regarding a set of criteria that need to be considered in both A+B with I/D and A+B without I/D contracts. This study shows how the owner would be able to adjust the UTV and I/D rates for A+B bidding projects by estimating the price-time curves of contractors. It would also enable contractors to adopt a more competitive strategy by estimating their competitors' optimal bidding strategies.

The experiences of hospital facility managers and consideration of the existing doctrines for commissioning building facilities have prompted the development of a new commissioning doctrine specifically conceived for health facilities by a special committee of the American Society for Healthcare Engineering. The new Health Facility Commissioning Guidelines present a doctrine calling for various tasks in the commissioning process from planning through hand-off to the health facility's operations and maintenance staff. Facets of this new doctrine are explained, differentiating it from existing doctrines that might otherwise be relied upon. The organizational implications of adopting this doctrine for the delivery of health facilities are intended to bring efficiency to the project delivery system and enhance the communication among different stakeholders. A project that is piloting this new commissioning doctrine is described, and lessons learned through the early stages of this project draw attention to the real challenges and practical solutions devised to address them. Student interns are being employed in the task of documenting and analyzing this pilot implementation. Their major findings illustrate the needs for future study.

Integrated project delivery (IPD) is attracting the attention of owners, seeking a more collaborative, shared risk, design and construction environment for high-performance building projects. However, the administration of a tri-party or multi-party contract requires a high level of owner involvement and experienced contractors. For owners considering an IPD approach, but unable or unprepared to pursue a multi-party agreement, several "IPD-lite" options are being tested within the construction industry. This research uses quasi-experimental observational case studies of four campus facility projects to follow the progress of the Pennsylvania State University's facility management organization, the Office of Physical Plant (OPP), through the development and implementation of a Collaboration Addendum as a supplementary contract attachment. Since the selected case studies are planned using traditional delivery methods, the Addendum was designed to integrate desired characteristics of an IPD approach, including: early involvement of project participants, collaborative decision-making, collocation and a performance-based incentive program. The development of the attachment followed a three step procedure of (1) defining the collaborative intent, (2) refining the intent on a project or team-specific basis and (3) outlining the desired process for achieving meaningful collaboration. Metrics for assessing the success of the Addendum were developed to determine the effectiveness of achieved levels of collaboration and included performance measures of timeliness of communication and meeting effectiveness. This paper reports the development and in-process implementation of the Addendum on selected case study facilities, as a means of promoting collaborative team behavior.

Construction project participants are becoming more aware of the costly and lengthy resolution of claims and disputes. This has led them to give more attention to the management of the resolution process. The International Federation of Consulting Engineers (FIDIC) included in its contract conditions a claim-dispute resolution timeline involving several steps starting with the minute a claim arises until a party initiates arbitration, in order to help parties involved in a certain project better administer claims. However, the period following the Engineer's determination and preceding the Dispute Adjudication Board (DAB)'s or Engineer's decision remained unregulated. The Literature does not tackle this specific period and the reason behind keeping it unregulated. This paper explores, through an in-depth reading of the 1999 FIDIC's conditions for contracts, this unregulated period by associating the claims during this period with various statuses. A framework is offered that shows how the status of a claim progresses during this period. The paper then sets follow-up steps for the statuses in the proposed framework. Finally, some concluding remarks and recommendations are proposed to manage this period.

Submittals are documents used by construction practitioners to exchange and document information about products, processes, and decisions made regarding what is to be used in a construction project. Shop drawings, samples, and product data are examples of submittals and used not only to convey information but they are also used to complete the design when construction projects are already under way. This paper presents a study of the submittal process in a mixed-use design-bid-build project in Southern California. During a six-month period the authors used a mix of quantitative and qualitative tools to build a chain of evidence related to how submittals were managed in the project. Swimlane diagrams showing the interactions between different project participants were built based on direct observation of activities, interviews, and analysis of documents. The authors have found that submittals that are reviewed by the general contractor with the subcontractors and suppliers before they are sent to the A/E have a higher success rate when compared to those not reviewed before submission. This shows that close collaboration between parties results in faster cycles of review and approval. The study sheds light on the need to manage the submittal process from a production system standpoint.

Construction projects are complex, from their design to the execution phase. Delivering a project on time is unpredictable due to the inherent uncertainty. Delays are normally considered to be an inseparable part of construction projects. Delays often lead to claims for costs incurred. Assessing construction claims caused by delays is complicated, as are the proceedings for achieving claim resolution. Loss of anticipated revenue, opportunity cost, increased overhead, cost escalation and liquidated damages are some of the main reasons for delay claims from key project stakeholders. A sound request for a delay claim must be supported by a reliable delay analysis technique. This paper discusses a new technique that is capable of evaluating concurrent delays. The technique is windows-based; therefore, it can trace all of the changes in the critical path(s). Apportionment of delay accountability may result in a false outcome if the effect of concurrent delays and changes in the critical path is overlooked. The procedures of this proposed technique are explained. The technique was tested against a hypothetical case and compared to existing delay analysis techniques with satisfactory results. The proposed technique allocates delays among the different project parties.

In heavy earthwork operations, optimizing equipment selection based on economical operational analyses has a primary role in the success of major construction projects. The main objective of this study is geared towards developing an automated optimization model in order to assist contractors in this multifaceted task. Economical operation analysis is conducted for an equipment fleet while taking into consideration the owning and operating comprehensive costs involved in most of earthwork operations. The proposed model is developed in a Microsoft environment using Visual Basic for Applications® (VBA) and is capable of being integrated with other estimating and optimization or simulation models. The implementation of the model provides optimum equipment fleet to perform earthwork operations based on their economical operation analysis by providing the user with a final optimized report that includes ownership and rental options. The model is validated through an actual case project to illustrate its numerical capabilities and to quantify its degree of accuracy. The results of this study are anticipated to be of major significance to contractors and would contribute to the database of fleet management systems by including a computer model that integrates heavy equipment operational analysis with its corresponding comprehensive economical analysis.

Construction of large-diameter drainage tunnels requires stringent line and grade tunnel alignment control in order to carry sewer and storm water in municipal areas. Tunnel boring machine (TBM) has been extensively applied to improve tunneling productivity and safety performances on drainage tunnel projects. The current practice for TBM guidance largely relies on the traditional laser system, which however falls short of accuracy and reliability. The proposed research aims to develop an automation solution to facilitate TBM guidance and as-built tunnel alignment survey in drainage tunnel construction. In contrast with our previous application of automating TBM guidance in microtunneling and pipe jacking for installing small-diameter utility pipelines, this research will address a related but more challenging problem defined in the context of drainage tunnel construction due to different construction methods and particular site constraints. An automation system is proposed, in which a robotic total station is employed to automate the continuous process of TBM tracking and positioning in the 3D underground space. ZigBee-based wireless sensor networks are applied for wireless data communication inside the tunnel. Real-time survey data are thus acquired and processed on the fly, resulting in: (1) TBM's precise coordinates in the underground space; (2) three-axis body rotations of the TBM; (3) tunneling chainage progress; and (4) line and grade deviations of the tunnel alignment. A prototype of the automation system was developed in-house and the lab testing carried out.

The improvement of pile driving productivity has been, for the most part, consistently neglected in the literature. In particular, the investigation of equipment technology improvements for pile driving activities has yet to be addressed. This study reports the process, benefits, limitations, and lessons learned associated with the definition, development, and implementation of an innovative extreme-batter (23.3° from the vertical) pile driving technology for the construction of a levee. The project team, in a collaborative effort, investigated alternatives to traditional extreme-batter techniques in order to minimize equipment and craft labor needs to complete the levee, and also to minimize the risk of safety occurrences. After holding brainstorming and technical feasibility analysis sessions, the project team decided to adopt an innovative fixed lead approach, the design and production of which was subcontracted out to a pile equipment specialist. Also, instead of subcontracting the piling activity, the team decided to self-perform it in order to have a tighter control on the levee construction process. The fixed lead technique resulted in a 40% cost reduction per unit length of driven pile when compared to traditional extreme-batter piling techniques. This paper also discusses the shortcomings associated the fixed lead pile driving technique.

With the impending end of the serviceable life of the National Highway System, many transportation agencies have increased their focus on preservation, rehabilitation, and maintenance projects. The Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) software has been a useful decision making tool for various Departments of Transportation (DOTs) in the United States. CA4PRS is a schedule and traffic analysis tool that helps planners and designers select effective and economical rehabilitation strategies. The Georgia Department of Transportation (GDOT) has investigated the applicability of CA4PRS for its concrete pavement rehabilitation projects. Results showed that two main issues for the use of CA4PRS in the state of Georgia were (1) the need for modifications to GDOT's operating procedures and (2) lack of data required for performing the CA4PRS analysis. This paper presents the initial steps in the evaluation of the data required for CA4PRS analysis of pavement rehabilitation projects in the state of Georgia. A comprehensive analysis of data collection practices was performed to determine required changes needed to satisfy CA4PRS software data requirements.

Growing market demands for improved lifecycle performance of facilities are increasing challenges in meeting project objectives. Integrated project delivery and BIM offer significant potential assistance in meeting these challenges, but require change by a set of activities that we will term construction engineering in this paper. The purpose is to identify and describe activities that improve project performance related to cost, schedule, quality, safety, and sustainability and to convincingly illustrate their importance. These activities include designing work process and temporary works, providing construction and permanent resources, and integrating work processes within and between project phases. For each of the major types of project objectives, this paper describes the requirements and implications for different types of projects and the construction engineering activities necessary to satisfy the objective. The applications and conclusions highlight the importance of construction engineering for success in meeting project objectives, the career benefits of this experience, and ways to realize these potential benefits.

Bridge construction has been closely monitored by government agencies, engineering and construction communities, and the general public. Previous research results show that to enhance the bridge construction operations there is a need to develop innovative technologies to improve communication and coordination among the participants involved in the bridge construction and to provide the labor working status information for project managers and engineers to quickly identify labor efficiency problems at the project sites. To address this need, a research project was conducted with the main objective of developing the Labor Working Status Monitoring Model that utilizes the Wireless Real-time Video Monitoring System and the benchmark data.

Pilot Tube Microtunneling, also referred to as the pilot tube system of microtunneling, guided auger boring, or guided boring method, is a trenchless construction method that is capable of installing pipes to pinpoint line and grade accuracy throughout the length of the bore. Pilot tube microtunneling evolved as a combination of three other existing trenchless technologies namely microtunneling, horizontal direction drilling and auger boring. The technology originated in Japan and Europe, and was first introduced to the United States in 1995. Since then this methodology has seen increased utilization across North America particularity in municipal markets for the installation of gravity sewers. This paper presents the results of a survey questionnaire of 22 pilot tube microtunneling contractors across North America, representing a total of 450 projects completed between 2006 and 2010, to determine the current industry state of practice in North America. The questionnaire examined various topics including contractor profile and experience; equipment, methods, and pipe materials utilized; and issues pertaining to project planning and construction risks associated with the pilot tube method.

We previously conducted a preliminary analysis of the tasks performed by operators of hydraulic excavators, where the excavator is stationary and the implement is controlled by joysticks operated with the left and right hands. In the present paper, we put forward a detailed comparative analysis of the tasks for a hydraulic excavator and those for a wheel loader, of which operation of the latter requires simultaneous coordination of vehicular driving and implement operation whereas operation of the former does not. These analyses, based on Hierarchical Task Analysis (HTA), illustrate the complexity of equipment operation and distinguish the skills to be acquired for each machine. By employing HTA to decompose complex tasks into a hierarchy of goals and sub-goals, a better direction may be devised for how trainees spend their practice time for both the simulator and real equipment training phases. Future phases of this research will include input from experienced operators and trainers and extension of the HTA analysis to finer levels of description, including cognitive tasks.

Construction performance and productivity improvement are key focus areas in construction industry for any nation. However many researchers have observed a considerable decline in construction productivity during the last two decades. Hence there is a strong need to find innovative methods to improve construction productivity, in terms of both labor and management issues. The purpose of the paper is to develop a Worker Performance Index (WPI) to enhance construction productivity. Based on site observations, interviews and examining of the current worker performance rating systems, initial list of factors were identified. Motivation, technical skills and management factors have been explored to define and evaluate the worker performance index. In addition to that, this paper considers the supervisor's overall assessment of the worker as an additional critical input. WPI is expected to assist the supervisors to assess the performance of the workers quantitatively for pre-construction planning and continuous improvement of the labor productivity.

Informed decisions on the efficacy of project and construction strategies to meet client objectives and satisfy project delivery constraints involve the three tasks of formulation, representation and assessment of alternative strategies. This need is present in not only the initial planning phase of a project, but during the execution phase as necessitated by changed objectives and conditions. Explored in this paper is a way of thinking about the concept of construction strategy and its interrelated parts (tactical variables and plan) in aid of the foregoing tasks, with particular emphasis on large scale vertical and horizontal building and civil infrastructure projects. This way of thinking has been pursued as a complement to other work directed at the visual representation and assessment of construction strategy alternatives in the form of 4D images, construction schedules, and related images, such as the distribution of resources in terms of time, space and physical system. Motivating this work is the pressing need to reduce impediments associated with exploring alternative strategies in a timely and insightful manner using existing scheduling and 4D modeling tools. Our strategy framework takes into account the dynamic factors of a project and consequences for strategy formulation and adaptation as positioned in the domains of time, space/system and project participant, and as driven by project directives.

Construction risk can be associated with different factors such as the size and complexity of the project, the experience of the contractor with similar type of work, unexpected weather conditions, unexpected ground conditions, or even unanticipated market changes. Failure to estimate the uncertainties that accompany a specific project often leads to a delayed project with cost overruns and compromised quality. Therefore, when bidding on a certain project, a contractor has to consider the possibility and the magnitude of construction risks involved, and then decide on its optimum markup accordingly. Cost uncertainty is not only an issue at the conceptual phase of a project but continues even into the construction phase. In addition to the uncertainty in the final project cost, the attitude of the contractor towards risk taking is of equal or even more importance in choosing the optimum markup and the resulting bid price for a project. This paper uses established principles of decision analysis and utility theory to develop a risk-sensitive bidding model that aims at determining the contractor's optimal markup value for a project given his risk attitude and his uncertainty about the final project cost. A sensitivity analysis is then conducted through a numerical example to illustrate the effect of risk aversion and cost variance on the optimum markup for the competitive low bid method.

To improve crew-level productivity, accurately measuring crew performance is the key issue. The accuracy of examining crew performance relies on the correctness and effectiveness of data collection. Some data collection techniques, such as productivity rating and five-minute rating, have their distinct advantages. However, they also have disadvantages in common. For example, the rating of effective work is based on observer's personal judgment that could cause different results from person to person. To overcome this drawback, a study for exploring the possibility of using heart rate and oxygen consumption to monitor crew's working conditions was conducted by the authors. Three types of work (effective work, essential contributory work, and ineffective work) were compared using participants' heart rate and oxygen consumption at work. Participants, aged between 23 and 25, were involved in assembling formwork in a laboratory setting. Experimental results indicate that oxygen consumption at work can be used to effectively distinguish between effective work tasks, but is ineffective at distinguishing some contributory work and ineffective work items. Heart rate at work is ineffective for distinguishing between some effective work and contributory work tasks, or between contributory work and ineffective work items.

In many highway construction projects, the time available to complete construction is set by the contract documents. Most transportation agencies have developed tools to assist project planners in estimating the amount of time required to complete the project but how accurate are these systems in estimating project duration? The current work examines the accuracy of integrated scheduling systems from two state transportation agencies in estimating contract time for previously completed Kentucky highway construction projects. The accuracy of the systems where tested against project data from 66 completed Kentucky Transportation Cabinet Projects. The analysis revealed that the average accuracy of both systems in predicting project duration was greater than ±200% across a variety of projects. A pilot study of the use of multivariate regression analysis of the data from 66 completed Kentucky Transportation Cabinet projects was performed to identify specific combinations of work item quantities with the engineer's cost estimate that produce the most accurate estimate of project duration. The accuracy of the developed regression equation in predicting highway construction project duration was ±25%. The current work contributes improved understanding of the accuracy of integrate scheduling systems in predicting highway construction duration.

Construction projects often encounter challenges during their execution that require careful mitigation - construction managers must optimally accelerate selected critical activities to still meet the deadline, but at an increased cost. The objective of a time-cost tradeoff is to identify options that balance these two counteracting factors. The dependency structure of schedules combined with often non-linear timecost relationships of their activities make tradeoff a complex problem. It eludes direct solution, but can be addressed algorithmically. Previous approaches could only model discrete relationships of activities and costs for network schedules. Linear schedules facilitate short project durations, but lack such methodology. This paper thus explores how versatile singularity functions, which capture changes in output for given ranges of input, can be used to enable tradeoff in linear schedules. It examines if it is feasible to establish the tradeoff curve for the overall project from the individual cost slopes at the activity level and illustrates its newly developed algorithm in a worked example.

Earned value management (EVM) is a methodology for evaluating project performance and progress by integrating project scope, schedule, and cost. EVM has been widely applied in various industrial sectors and many studies have been conducted on EVM and its application in the industry. This paper provides an analytic review of EVM studies and its applications. EVM studies published in a number of sources are reviewed. These studies are classified as either empirical or non-empirical. For empirical studies, key issues reviewed include effective implementation of EVM, behaviors of cost performance index, accuracy of cost control techniques, and accuracy of time control techniques. For non-empirical studies, key issues reviewed include schedule performance index, accuracy of time control techniques, and the integration of EVM with other project management techniques.

Fast-track construction projects have become more popular in recent years in response to growing industry demand. By allowing a downstream activity to start with incomplete information from upstream activities, fast-tracking allows for shortening the project duration at the expense of an increased likelihood of rework. This leaves practitioners with the challenge of determining the optimal fast-tracking strategy, which meets project schedule requirements and does not cause excessive amounts of rework. This paper presents an optimization based model that serves as a decision support tool in scheduling fast-track construction projects. The model takes into consideration information exchange between upstream and downstream activities. The objective function of the model is to maximize the net benefits from fast-tracking. Rework time and cost are deduced from the literature on rework in construction projects. The model is illustrated on a small scale case study, which was analyzed under various scenarios. The paper concludes with a discussion of the applicability of the model on complex construction projects.

Tunnel construction involves complex projects that encompass various types of risk. To achieve project goals, contractors need to adopt appropriate risk management strategies from project inception to project completion. In this paper, we present and analyze the risk-response measures employed by tunneling contractors in Thailand and their major criteria for choosing such measures. Thirty-nine risk factors proposed by previous research as borne by tunneling contractors were compiled and verified by experienced tunneling engineers. Alternative risk-response measures for each risk factor employed by tunneling contractors were identified, including risk-retention, risk-reduction, risk-transfer, risk-avoidance, and contingency allowance. It was found that the most commonly used risk-response measures were risk-reduction, risk-retention, risk-transfer, and risk-avoidance, in that order. We also identified the major criteria that contractors consider when choosing the appropriate risk-response measures for each risk factor, such as cost, project delivery system, and project payment method. Tunneling contractors can use these results as a guideline for developing appropriate risk management plans for future projects.

The paper presents the findings of a study conducted at a large 360-bed and 730,000+ square feet hospital in Southern California. The main purpose of the study was to investigate the work flow of trades working on the project site and to identify problems that prevent a continuous flow of work of dry wall, electrical, and mechanical trades working in different rooms. Data was collected through different methods including direct observation of the work and trade meetings, document analysis, value stream mapping, and interviews. The paper focuses on a specific area of the project related to building repetitive units (rooms and bathrooms). A large portion of the lead time to complete the units was related to waiting/idle times resulting from problems in the information flow and especially how people make commitments to execute these tasks.

This research shows that project soft costs expressed as a percentage of construction costs have been increasing in the past 40 years in transit projects constructed in the United States. Soft costs are those costs not directly spent on activities related to the construction of a project (i.e., hard costs), but are necessary capital expenses to plan, design, and manage the project in order to ensure the successful completion of the project. Soft costs are a significant portion of transit project development costs, accounting for about 30% of construction costs on average. The magnitude of these costs varies widely for different projects and depends on several factors. An examination of actual costs for more than 50 transit projects in the United States shows that the soft costs vary between 10% to over 50% of construction costs. In this paper, actual costs of 51 transit projects constructed in the United States is studied. Factors affecting the soft costs in these transit projects are analyzed and using relevant statistical techniques, the less important factors are systematically eliminated in order to identify the most significant factors that drive project soft costs. The significance of these factors and their impact are measured using a multiple regression approach. The regression methods used for selection and inclusion of the most significant project characteristics include: forward selection, backward elimination, stepwise regression and best subsets approaches. Using a combination of these statistical methods, a short list of project characteristics is identified that contain major contributors to project soft costs. These characteristics include mid-year of expenditure, length of project development phase, procurement method, number of stations, percent below grade, and type of project (new vs extension vs rehab). One of the major findings is that the mid-year of construction has been a significant factor in the magnitude of soft costs as measured as a percent of construction costs. For the past four decades, soft costs have increased 4-5% per decade as a percent of construction costs in transit projects. The study is strictly statistical and does not investigate the causes of this trend; however, the trend is alarming and it would be appropriate to investigate the causes of this trend.

Struck-by injuries are a leading proximal cause of fatal injuries and are usually caused by a falling or suspended objects and contact between workers and heavy equipment. As with other injuries, struck-by risks are most effectively mitigated early in the planning phases of a project. Among different methods of preconstruction safety management, safety risk modeling and integration has been shown to be highly effective. To enhance the current preconstruction safety management methods, the authors utilized an attribute-based risk identification and analysis method that helps designers and preconstruction planners to identify and model safety risk independently of specific activities or building components. In order to identify the attributes that contribute to struck-by incidents and quantify their relative risks, over 300 injury reports from the National databases reviewed. In total, 34 attributes were identified and their risks were then quantified. It was found that working under or near lifted loads (15.6%), working with heavy equipment (17.1%), workers on foot and moving equipments (13.5%) are the most hazardous attributes that lead to struck-by accidents. The results can be used by practitioners to integrate robust safety risk data into project designs, schedules, building information models, and pre-task plans.

The risk associated with constructing multistory commercial buildings can take many forms, with significant risk associated with construction site safety hazards. The type and magnitude of risk present on construction sites depends to a great extent on the permanent design features. A project's design forms the basis for the means and methods used during construction. If the risk factors associated with design features are known, risk management can take place during the design stage to select design alternatives which minimize construction safety risk. As part of a recent research study, design risk factors were quantified for all of the construction activities and equipment necessary to construct the shell of a multistory commercial office building. The risk factors were developed through detailed input from general contractor superintendents, general contractor safety managers, and trade contractor personnel. For cast-in-place concrete, for example, the research results indicate that there is no evidence of a difference in risk perception between general contractor superintendents and general contractor safety managers in terms of risk ratings for the activity risk, severity, and total risk. The construction and removal of formwork and pouring of concrete show moderate to suggestive evidence of a difference in the sample mean risk perceptions for the three group comparisons. There is moderate to suggestive evidence of a difference for medium severity, high severity, and total risk for the three group comparisons. There is no evidence of a difference in the way the groups perceive near miss risks. The research results allow for comparison between different design alternatives as well. For example, for steel stud versus concrete masonry unit (CMU) block partition walls, there is moderate evidence that on an average, the construction of CMU block wall has a larger cumulative risk of medium severity and high severity injuries. This paper presents comparisons of risk perception between the three sample groups for different design alternatives, along with comparisons of the perceived risk between different design alternatives, to illustrate the differences in construction safety risk expected during construction.

Many studies have revealed that the productivity of the construction industry has been exhibiting an increasingly lacklustre performance, despite the fact that the last century witnessed the most radical advancements in the technologies. The paper critically analyzes the contemporary measures in productivity control and management practices based on an investigation conducted on construction processes, documentation, perception, productivity personnel, and awareness focusing on a number of construction projects both in Canada and the United States. The observations were verified and justified based on the responses from the construction industry personnel. Results of the analysis of contemporary productivity practices and potential issues are further elaborated and discussed in detail in the subsequent paragraphs. The paper also elaborates all the insights and the inferences resulted in the preliminary study, from a new perspective that proposes to practice productivity control and management as a mainstream function complementing overall project management process with objectivity in implementation by way of a dedicated/committed person and a structured framework of actions. The paper further extends to introduce the basic concepts of the new Construction Productivity Improvement Officer (CPIO) role. The CPIO concept is further discussed related to its approaches towards addressing the key issues identified as lack of accountability, poor integration of isolated tasks, discrete functionality, lack of planning and controlling measures.

Uncertainties are one of the greatest impediments to construction planning and decision-making. Events such as unforeseen site conditions, equipment breakdowns, and late material delivery can affect activities on the critical path, significantly delay the project, and potentially increase the project completion cost. The dynamics involved in most construction projects make it almost impossible to predict all events that may adversely affect a project operational plan. As such, project plans need to be constantly adapted to the real situations during the construction phase. This requires that the latest information about the status of all project entities (including equipment) be collected. Among different classes of construction equipment, cranes are among the most expensive, and activities that rely on crane service usually fall on the project critical path. This implies that the monitoring and analysis of crane related operations is essential to enhance productivity. This paper presents the latest results of an ongoing research which aims to facilitate the planning and control of crane operations by capturing and analyzing data corresponding to a crane's physical movements. The result of this analysis can be used to identify parameters describing different phases of crane operations in order to better predict the performance of crane-related tasks.

Selecting an appropriate project delivery method is a complex decision-making process due to risks and uncertainties. At the time of the decision, the owner and stakeholders often have little information and the project plans are not detailed enough to make a judgment about the project with certainty of outcomes. This paper examines 39 risk factors related to the project delivery selection process. These risk factors were identified through completed cost and schedule risk analysis on more than $100 million of highway projects. A questionnaire was developed to collect the data a cross section of three delivery methods, including design-bid-build, designbuild, and construction manager/general contractor. Experts with an average of 25 years of related experience were invited to participate in the survey. The results indicate that the four risk factors that have most influence to all three delivery methods are: unexpected utility encounter; third-party delays during construction; geotechnical investigation; and delays in reviewing and obtaining environmental approvals. The research identified five other risk factors that have varying impacts on project delivery selection constructability of design; delivery schedule; railroad agreements; obtaining other agency approvals; and scope definition. This study also discusses the pertinent findings and rationale behind the critical risk factors.

The construction industry is one of the largest and most dangerous industries in the US, where in 2009 the industry accounted for 834 deaths; more than any other industry. The incidence rate of 9.9 deaths per 100,000 workers puts the construction industry in fourth place behind the Agriculture/Forestry/Fishing/Hunting, Transportation/Warehousing, and Mining sectors (BLS 2011). The cause of a large number of these construction deaths can be attributed to factors that are distant from the construction site. A European study has shown that 60% of fatal accidents in construction are caused by decisions made "upstream" from the construction site (European Foundation 1991). Similarly, an Australian study showed that 63% of fatalities and injuries are attributed to a lack of planning and design decisions (NSW Workcover 2001), while in the US, Behm found that 42% of construction site fatalities can be linked to design (Behm 2005). With such overwhelming evidence, foreign governments have initiated efforts to make designers aware of the impact of their decisions and design choices. These efforts include new legislation and improved guidelines (EEC 1992; NSW Workcover 2001) that aim to reduce the construction hazards linked to design. In the US, designers are mostly unaware of the concept of Design for Construction Worker Safety (DCWS), or even that their design decisions can affect the safety of the construction workforce. Professional organizations regularly resist change and refuse to even consider participating in the DCWS concept that would eventually assist in the improvement of construction site working conditions (Toole 2011). The research presented in this paper represents the results gathered from a survey of the opinions of the primary construction industry participants (owners, designers, and contractors) on the topic of DCWS. The population of the survey was obtained from four different groups. Contractors who responded to the survey were randomly selected from the Associated General Contractors of America (AGC) directory. Designers were randomly selected from two sources: the American Institute of Architects (AIA) directory and the American Council of Engineering Companies (ACEC) directory. To represent owner organizations, the researchers chose to include university representatives who participate in the construction of facilities on US university campuses. Through the survey, the authors investigate the extent of the acceptance of DCWS by industry participants, their opinions and identification of perceived obstacles or enablers of the concept, and the types of safety measures or safety plans they currently implement. The results of this research will assist construction professionals in determining the framework for a successful implementation of DCWS in the US construction industry. The implementation of DCWS by US professionals in their designs is important in an international construction market. Since DCWS is part of the design process in other countries, US designers wishing to practice in locations where DCWS is enforced by legislation, will find themselves at a disadvantage.

Construction companies need to continuously improve construction productivity to stay competitive. One of the main means to achieve construction productivity improvement is to reduce the uncertainty about, and to increase the command and control of, construction processes. Most of the current productivity management practices assess and control the productivity in a reactive manner, which take corrective actions only after the problems (such as when there are schedule delays or lower than expected production rates) are identified. Instead of relying on reactive responses to problems, we propose to proactively prevent problems by identifying and removing information bottlenecks before construction activities start. We consider assumptions as a major source to identify information bottlenecks that are associated with construction processes. In order to support proactive construction productivity management, we have developed a framework to capture assumptions made during construction processes and to reduce the uncertainty through proactive verification of the assumptions. This paper presents the vision for such a framework, and demonstrates the nature and required functionalities of the framework.

Evolutionary Algorithms (EAs) as appropriate tools to optimize multi-objective Time-Cost-Resource problems have been applied to optimize construction projects in the last two decades. However, studies on improving the convergence ratio and processing time in the most applied algorithms such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Ant Colony Optimization (ACO) in construction engineering and management domains remain poorly understood. We apply our fuzzy enabled Shuffled Frog Leaping Algorithm (SFLA) approach to solve optimization problem, which is found in the construction project planning literature. Our proposed approach uses splitting allowed during execution of activities as a significant reality of actual construction projects in this hybrid algorithm. It is shown that our proposed fuzzy enabled SFLA approach with activity splitting allowed is superior than existing optimization algorithms in finding better project schedule solutions with less total project cost, less total project duration, and less total variations of resource allocation.

WorkFace Planning is a construction planning and execution process developed by the Construction Owners Association of Alberta to enhance construction projects in terms of cost and productivity performance. To evaluate its effectiveness on labour productivity, a study is being conducted with a major Canadian industrial construction group that uses WorkFace Planning. In order to reliably establish a relationship between the planning process and improved project performance, a mathematical formulation is needed to capture the effects of WorkFace Planning on labour productivity. This paper presents a mathematical framework that quantifies the changes in both labour productivity and inproject costs that come from mitigation strategies developed through WorkFace Planning. The framework will be used in a research study that examines the proposed connection between WorkFace planning and improved project performance in depth.

Lack of financing and cash deficit is considered as a primary threat to contractor's financial management. Therefore, in case of insufficient cash, many contractors find it difficult to stick with the project schedule leading to extra overhead costs and liquidated damages. Mainly contractors deal with the project scheduling and financing as two independent functions of construction project management. Thus, the main objective of this research is to develop a multi-objective elitist Nondominated Sorting Genetic Algorithm (NSGA-II) for solving finance-based scheduling problem of multi-projects with multi-mode activities. A CPM scheduling model is constructed with its associated cash flow to calculate the values of the multiple objectives. The problem involves the minimization of conflicting objectives: duration of multiple projects, financing costs, and maximum negative cumulative balance. The designed optimization model performs operations of NSGA-II in three main phases: (1) Population initialization; (2) Fitness evaluation; and (3) Generation evolution. An application example is analyzed to illustrate the use of the model and to demonstrate its capabilities in generating optimum solutions. The model can be considered relevant for practitioners to use in large construction projects to make decisions regarding financing.

Construction site is a dynamic environment in which workspaces of construction activities continuously change in aspects of space and time throughout the entire lifecycle of a project. Without a comprehensive plan that considers spatial-temporal relationships between the site objects, conflicts or improper layout may frequently occur on construction site and influence the success of the project. Four dimensional (3D+time) modeling technique has been proven to be useful and promising in construction planning. However, it still lacks the ability to capture the site dynamic natures and analyze spatial-temporal relationships. The overall goal of this study is to develop a 4D topology system based on GIS concept for construction planning, which enables deriving 4D relationships between site objects in real-time and provides a comprehensive 4D topological analysis function, overcoming a major drawback in the current 4D practice. This paper presents the result of the development of the 4D topology framework in construction. The semantics of 4D topology are defined to describe corresponding dynamic construction site events. A 4D topological framework is formalized to capture the site dynamics which forms the base for 4D analysis. It could complement the CPM or 3D model in construction planning under both spatial and temporal constraints. The direction of future research in 4D topology-based analysis is also discussed.

Studies have established that construction workers are more likely to be injured than workers in other industries. In the United States, the construction sector has accounted for more than a thousand fatal injuries every year between 1995 and 2008. Although injury rates have reduced substantially in the past decade, the construction industry still accounts for the most on-the-job fatal injuries of any industry. Also, it has been suggested that the observed reduction in injury rates may be attributed to fiscal constraints that resulted in 17% decline in the number of hours worked, rather than the improvement in safety performance. A large portion of construction injuries occur because new workers lack the ability to predict, identify, and respond to hazardous conditions in dynamic work environments. In order to improve workers' situational awareness, employers often put new workers through hazard recognition training programs. Unfortunately, there is no industry standard method of hazard recognition. In an effort to identify the most promising hazard recognition programs for construction, the research team (1) conducted focus group sessions with a panel of fifteen industry experts; and (2) reviewed literature to identify hazard recognition techniques. The results of this study can be used by practitioners to strategically identify potential hazard reception programs that complement existing methods. Researchers may build on this study by further investigating the most promising strategies by testing them with active crews, measuring their effectiveness, and determining the most cost-effective methods that could potentially become industry standard.

Preliminary engineering cost is one of the essential components of a roadway project which accounts for on average 7% - 20% of an overall project cost. A reliable estimate of preliminary engineering (PE) cost is critical for highway agencies for allocating budgets, completing projects on time, and reducing public inconvenience. However, many highway agencies do not have a prediction system or mechanism to estimate their PE costs and usually utilize engineers' judgment in estimating PE costs. In addition, these agencies outsource approximately 50% of their design works to consulting firms due to insufficient in-house design capabilities and typically utilize excel-based fee proposal spreadsheets for negotiating the design fee with the consulting firm solely based on project type. This study investigates critical factors that should be taken into consideration to develop a reliable PE cost prediction model based on ten years of roadway project data collected from the Oklahoma Department of Transportation (ODOT) engineering division. This study conducts a factor analysis of a covariance and correlation matrix to investigate the significance and correlation of critical factors affecting PE cost. Then, the study presents data driven and component based PE cost prediction models of PE costs by utilizing a knowledge discovery in database (data mining) techniques. Based on the study, critical factors affecting PE costs were classified into five major categories; project scope, geographical attributes, design attributes, environmental attributes, and external factors. It was identified that roadway length, location, and highway type were highly correlated with PE costs. For this paper, a combination of knowledge discovery in database methods (regression models, and decision tree models) are developed and compared to obtain the optimum PE cost model as a function of a) engineering hours required per number of sheets, b) number of sheets and c) cost per engineering hours for the various plan development tasks. A comparison of these models resulted in decision tree model to be the best model for predicting PE costs. The results of this study will greatly influence how efficiently and economically roadway projects are planned, executed, managed, and gives more accurate accountability of project developments during the early phases of a roadway project. In addition, the model will not only allow ODOT to be equipped with a streamlined procedure for estimating PE costs but also facilitate consistent practices and structured format of PE cost estimating.

Today change is a major challenge in construction projects environment. Identification and assessment of changes occurrence paths is an important tool for promotion of changes management systems. A method for assessing a complicated phenomenon such as "change formation" is breaking them into tangible elements. Using separated concepts, the steps for changes occurrence paths have been formed. These concepts include change sources, change drivers, change causes, change requesters, and affected project parties. By using dynamic programming method an approach for identifying of changes formation scenarios based on changes occurrence paths has been presented. Finally, the developed approach has been illustrated with a case study. Based on this approach decision-makings would be made with a better understanding of probable scenarios of change formation at the early stages of projects. The developed approach could be used for development of a system for predicting changes in construction projects.

Semiconductor manufacturing facilities are very complex and capital intensive. Construction of these facilities often involves high levels of uncertainty, strict spending limits, aggressive schedules and fast track construction. Different disciplines generate and require a tremendous amount of building and manufacturing process information to support decisions that enable the successful design, construction and operation of these advanced facilities. In the highly fragmented construction industry, a majority of the information and processes throughout the life cycle are neither integrated nor interoperable and result in a high degree of redundancy. The semiconductor manufacturing industry in its constant quest to minimize the cost of these facilities and speed project delivery to match production to meet the available market window is implementing Building Information Modeling (BIM) to achieve these goals. This research focused on building an interoperable tool model to characterize the information exchange necessary between base build construction and tool installation in a semiconductor manufacturing facility. It examined existing standards to facilitate the data exchange process and standard development needed to assist in implementing intelligent facility and tool models. Information modeling for a semiconductor manufacturing facility is unique in that it is a process model (Tool Information Model) within a building model (Building Information Model), each supported more robustly by different interoperability standards. To facilitate flow of information between the different domains a mapping of the industry standards must be undertaken and translators developed for business use.

Many construction projects are becoming more complex and large in scale due to advances in technology and operations. These projects involve many stakeholders, with different geographical locations and working cultures, collaborating with one another throughout the project life cycle. Industry leaders believe that interface management systems can be created to improve alignment between stakeholders and reduce project issues and conflicts. However, identifying interfaces and monitoring interface states are significant challenges that creates a continues struggle for owners. Interfaces are generally considered as the links between different construction elements, stakeholders and project scopes. Poor management of interfaces may result in deficiencies in the project cost, time, and quality during the project life cycle execution, or may result in failures after the project has been delivered. Therefore, having systematic interface management to effectively handle the interfaces through the project life cycle is critical to project performance. In this paper, a process based approach is proposed for interface management of mega capital projects, starting with the definition and taxonomy of interfaces. Then, the main steps for implementing an Interface Management System (IMS) are introduced: (1) interface identification, (2) documentation, (3) issuing, (4) communication, and (5) closing.

Engineering News Record (ENR) publishes Construction Cost Index (CCI) monthly. CCI is widely used by cost engineers for preparing cost estimates, bids, and budgets for capital projects. CCI is subject to significant variations. The information available from historical time series data on some economic variables (federal funds rate, consumer price index, gross domestic product and unemployment rate), energy-related variable (crude oil price), and construction market variables (housing starts, employment level in construction, and construction spending) may be useful for explaining CCI variations. The research objective of this paper is to empirically examine whether the time series information on the above economic, energy, and market variables is useful to explain CCI variations. We devise time series tests like Pearson correlation test and Granger causality test to statistically examine the impact of each variable on CCI variations over time. The results show that the information available from historical data on consumer price index, gross domestic product, crude oil price, housing starts and employment level in construction is useful to explain variations of CCI. It is concluded that the information available from historical data on federal funds rate, unemployment rate, and construction spending do not have power to explain CCI variations. This empirical study is expected to increase our understanding about the impact of various economic, energy, and construction market variables on CCI variations. It is anticipated that this knowledge will be useful for cost estimators and capital project planners to explain changes in construction cost over time.

Project scheduling is an important task in program management. The selection of resources and the harmonization of their work make program scheduling crucial for the success of a construction program for both the owner and contractor. To achieve long term economic, social, and environmental benefits, program managers need tools that can help them assess their program's sustainability performance. Indicators are recognized as useful tools to measure performance across a range of sustainable principles. The multimode resource-constrained project scheduling problem (MRCPSP) deals with the scheduling of a set of projects with alternative requirements of resources to execute them. Minimization of project duration is usually considered as the objective; however, social objectives may impact the performance of projects and affect program sustainability goals. To account for this new social input, this paper adapts a mixed integer programming (MIP) model that solves the MRCPSP problem. Aside from the social objective, the model accounts for renewable resources and non-renewable required by projects during their life span. A literature search is undertaken to determine an indicator to assess performance with the objective of maximizing social sustainability of construction projects. The proposed model can be a valuable tool to assist in an industry that is moving towards sustainable practices.

The lack of meaningful performance metrics, infrequent assessment of project deficiencies and inaccurate prediction of client satisfaction result in misaligned design/construction project management strategies. This misalignment results from ‘bad' performance monitoring practice according to recent research in applied microeconomics using global manufacturing firms. ‘Good' practice was shown to be strongly associated with higher firm performance measured by productivity, profitability and survival rates. No such evidence was found in the AEC industry. We develop a frequent metric-based feedback method to predict client satisfaction. The metrics and method are theoretically founded and empirically derived using one major longitudinal case study with a healthcare organization. Management effectiveness literature on construction KPI's and strategic management literature on Total Quality Management help us define the predictor metrics. Preliminary analysis based on the first ten months of data collected show that our proposed metrics could reliably predict client satisfaction. Historically, organizational behaviorists have found that feedback effects on performance to be quite variable - not always positive. Our results show that there is higher predictability in client satisfaction with performance feedback than without. Our findings provide initial insight in guiding project execution teams to tactically manage client satisfaction.

Risk is inherent in construction projects of all types and sizes. It has many causes and its effects manifest themselves in various forms. Most recognizable are impacts on the schedule, where they reduce float, i.e. its flexibility to absorb delays and thus mitigate risk. Regardless of the nature of risk, it is measurable by its effect. Several important issues arise, including how to allocate float fairly and equitably among subcontractors, valuing it for trading it before it expires, and using so that optimally mitigates the risk of the overall project. This research therefore explores one of these three parts of an improved risk management methodology, valuation. It uses real options, which model opportunities - not obligations - for decisions on tangible assets, to price allocated float for trade among critical project participants. The binomial decision tree or lattice of real options is analogous to junctures within network schedules. At such points participants may use or trade non-expired float to reduce delays along or near a critical path, or reserve it to hedge against future risk until it expires. In other words, it functions like put and call options. Overall, this study extends theory in construction risk management by pricing tradable float.

Construction of Industrial facilities involves a substantial amount of piping. Pipe spools are usually pre-fabricated from a number of raw pipes and pipe fittings (e.g. elbows, flanges, tees, etc.) in fabrication shops. Pipe spool fabrication is often affected by various disruptions from within or outside the shops. Previous research mainly focuses on shop layouts, dispatching rules, buffer location and standardized products. Another critical factor, the sequencing of pipe spool fabrication, is usually overlooked. A pipe spool can be fabricated in several alternative sequences that are often decided by shop foremen based on experience. It is rare that these alternative sequences get compared and evaluated. A simulation experiment shows that shop productivity can be improved by varying spool fabrication sequence. This paper presents an investigation of Artificial Intelligence (AI) planning approach that automatically identifies the optimal fabrication sequence for pipe spools while considering various fabrication logics. Experiments are conducted with different AI planners to evaluate their capabilities. The results indicate that one of the planners is more suitable for solving the sequencing problem than others. However, it requires special pre-processing of the input that may be prohibiting for practical use. Directions of future research to overcome these limitations are discussed.

Preliminary engineering (PE) is a critical preconstruction phase of infrastructure projects, encompassing the initial planning and design processes necessary for successful commencement and completion of a project. The duration of PE influences both the cost and schedule of any civil infrastructure project. Numerous studies targeted at construction duration estimation exist, but few address strategies to estimate PE duration. This study sought to identify the project factors that influenced the PE duration of bridge projects and to determine if regression modeling with those factors would provide a feasible tool for PE duration estimation. Some 416 bridge projects conducted by the North Carolina Department of Transportation (NCDOT) served as the analysis sample. Among the project factors investigated, four descriptive factors significantly influenced PE duration: geographical area of the state, classification of the required National Environmental Policy Act (NEPA) document, bridge construction scope, and responsible party preparing the NEPA document. For validation purposes, the authors randomly extracted 60 of the 416 bridge projects before regression modeling. Regression models achieved a mean absolute percentage error (MAPE) of 21% when applied to the validation set. Comparatively, using the mean PE duration of 66 months as a single point estimator, the MAPE was 22% for the same validation set. Based on these results, the project team recommended that the NCDOT can use the regression equation to estimate PE duration. It is also clear that this is a difficult problem that deserves further research attention.

Which constructability methods are effective in preventing which problems and to what degree? This research explored the relationships between 12 of the many "constructability methods" identified in the literature and a set of 17 basic constructability problem types that were isolated through rigorous investigation of the detailed histories of four large construction projects. The resulting relationship matrix represents the potential causal connections between the constructability problems and the constructability methods that can prevent them. Experts were interviewed to determine the values of the cells of the matrix, and their input was analyzed to draw conclusions dealing with the priority of implementation of constructability methods as well as the potential of the various basic problems to be prevented by the implementation of constructability methods. The most effective tool was found to be assigning a design manager as a "constructability champion," while the type of problem that could be prevented most easily was identified as technical coordination. Surprisingly, company procedures such as ISO 9000 were found to be one of the least effective methods.

Mobile operations and highway maintenance work is among the riskiest activities of state highway agencies. Over the past ten years, approximately 1,300 fatal and major injury crashes occurred in Iowa with 8,200 minor injury crashes, 11,400 possible injury crashes and 34,000 property damage crashes, as reported in the statewide crash database of Iowa Department of Transportation (DOT). A literature review finds very few studies that have analyzed risk in moving operations and maintenance work using an integrated, system-level analysis. The study reported herein provides a broad examination of the different risks identified and assessed through qualitative analysis involving conducting interviews and national surveys to identify the critical factors with respect to their severity and likelihood of occurrence and developing suitable risk mitigation strategies. The analysis resulted in nine factors bearing catastrophic risk potential for maintenance and operations in highways that require immediate attention. These are (1) night time operations; (2) peak traffic hours; (3) absence of proper signage near the work-zone; (4) improper signs and signage at ramps and roadway intersections near work-zones; (5) work-zones on roads in hilly areas; (6) foggy-misty weather; (7) not using morning lights in the work-zone; (8) not imposing speed limit fines on public; and (9) lack of work safety and training programs.

Contractors are frequently required to provide detailed schedules soon after award of contracts. Owners are to evaluate and subsequently approve these schedules. The approved schedules are then used to generate project's baselines; necessary for tracking and progress reporting as well as administration of construction disputes. As such, it is important to insure the goodness of these schedules. This paper provides a structured methodology to assist owners in performing such schedule assessment and evaluation. In essence, the developed methodology serves as a check list that covers a set of overall requirements for good schedules. The methodology is based on integration of scattered knowledge. The developed methodology has been implemented in automated computer application encompassing three tiers of schedule assessment to facilitate effective evaluation of detailed schedules. This is particularly useful in performing schedule assessment of large projects, which have hundreds, if not thousands, of activities and may involve owners' participation in schedule development. This paper provides an overview of the developed system and describes its basic components. An actual project schedule is analyzed to illustrate the essential features of the computer application. The developed application can also be helpful to contractors; serving as guideline and recommended practice in scheduling.

This paper presents a new method for forecasting time and cost of construction projects at completion and/or at any intermediate time horizon. The method is designed to overcome limitations of current applications of earned value method in forecasting project cost and durations. The method adopts recently introduced extensions to EVM and the project ratios technique for progress reporting. It introduces modifications and developments that allow more accurate and practical results. Unlike the current applications of EVM method, the proposed method uses simulation to generate stochastic S-curves based on past performance achieved by contractors. The method enables the user to assess the uncertainty associated with forecasted project cost and duration at completion so that appropriate corrective actions can be taken, when needed. A numerical example is presented to demonstrate the use of the proposed method and to illustrate its improved forecasting accuracy over current methods. The results obtained by the developed method demonstrate the effectiveness of (1) using project ratios technique in forecasting project time and cost comparing to that obtained by traditional EVM method; (2) measuring the status of critical activities only, is particularly useful in forecasting project durations; and (3) accounting for uncertainties involved in the forecasting process provides flexibility in modelling forecasted project time and cost.

Target value design (TVD) is a management method for integrated project delivery (IPD) through the collaborative efforts among different stakeholders. This study uses game theory to explain how TVD fundamentally enables each stakeholder to collaborate on initial design alignment. According to the prisoner's dilemma, two people locked in separate jail cells tend not to cooperate even if their cooperation could bring maximum benefits to both of them because each one suspects the possibility of being betrayed by the other. In a similar way, it is easily found that each stakeholder, such as an architect/engineer or a contractor, does not make the effort to collaborate aggressively in their early alignment. For example, they traditionally prefer point-based design to set-based design because the latter can merely amount to service for free. However, if a detective interrogates two prisoners together in the same space, two prisoners can cooperate, preventing them from betraying each other. Similarly, if an owner provides a medium for communication and strongly trusts the stakeholders with a contract or an incentive, they can find optimized solutions for maximizing their value while minimizing opportunism for their own benefit. With the context of game theory, this study compares the Design-Build delivery system with IPD based on TVD in light of collaborative design alignment. Based on this comparative application, this study shows how a set of managerial target costing strategies to shift from traditionally dominant behavior to cooperative management practice. This kind of economic approach is expected to be helpful for understanding the governance of cooperation among stakeholders for IPD.

Construction-related practices are facing enormous pressure for change because of low productivity, the lack of sustainability and the often poor quality of delivered buildings. New methods and tools have been proposed to address the problems associated with the fragmentation of tasks, disciplines and responsibilities that contribute to the industry's poor performance. However, there is still no unified proposition to guide the industry in rethinking and integrating their practices. There is obviously a need for a framework that combines work processes, technological means, normative aspects and domain knowledge. This paper proposes a model for such a framework; a combination of the Integrated Design Process (IDP) and Building Information Modeling (BIM) for sustainable built environment. Its theoretical background draws from studies in social learning (activity theory and situated action theories). These theories suggest that learning and knowledge generation occur mainly within a social process, defined as an activity. This corresponds to the context in which the IDP-BIM framework would be used, as its final objective is the transformation of building design practices. Two validation scenarios are under development and observation: one evaluates how the Framework helps to create a common language among different building specialists, and the other assesses the ergonomics of the digital interface.

In the past two decades more than 26,000 U.S. construction workers have died at work. Of these fatalities, 40% involved falls. It is indicated that safety in construction remains a big problem. Safe construction requires planning throughout the project lifecycle, from design, planning, through construction execution and extending into operations and maintenance. The literature and past research show that there is a lack of tools and resources to assist designers and engineers with addressing construction safety. Despite the implementation of safety practices, most of them applied in the field are primarily text-based checklist. Further improvements can be gained in construction safety through the use of technology. This paper contributes in solving this problem by developing a framework of automatic safety checking to Building Information Models (BIM). The presented framework and case study extends BIM to include automated hazard identification and correction during construction planning and in certain cases, during design. As a result, the developed automated safety checking platform informs construction engineers and managers in knowing, why, where, when, and what safety measures are needed for preventing fallrelated accidents before construction starts.

Design process is complex and tightly linked with product model. Since, sophistication in the product models increase with emerging modelling tools, the process complexity also increases, demanding support of process modelling tools. This paper emphasises the need for integrating the process with product model in Architecture, Engineering and Construction (AEC) industry. A product-process integration model is proposed to apply the concept. Building Information Modelling (BIM) is a recent technology for developing product models in AEC industry and Design Structure Matrix (DSM) is a proved process modelling tool, capable of representing iterations in design process and optimising sequences. A pilot case study of integrating DSM with Industry Foundation classes (IFC), an open format of BIM, is used to demonstrate working of the model.

Simulation models are knowledge intense computational entities. Simulation model development consumes lots of time and resources. The research described in this paper is motivated by necessity of reuse, composability and interoperability of the construction simulation models. The innovate architecture presented in this paper blends semantic web technologies and construction simulation models presented in a machine interpretable metadata for storing, sharing and discovery of knowledge within construction simulation models and properly linking them to their related information sources. For this purpose a repository of construction simulation models has been developed. Construction modeling repository mainly contains simulation templates and models and other relevant sources. Sharing and integration of these simulation componets enables inference and extraction of meaningful information through structuring queries.

BIM in the FM industry has significant impact on the acceleration of design and construction phases of equal importance. However, most of the facility managers are still managing the maintenance and operations of facilities by using paper-based processes that include drawings and spreadsheets. Therefore, we propose the conceptual BIM acceptance model in FM for understanding why people accept or reject BIM. The objective is to understand the key factors affecting the acceptance of BIM by facility managers. The external and internal variables identified through a literature review with respect to understanding the acceptance of new information technologies, and then to select external variables to increase BIM acceptance in FM. And the interview refines the constructs of a conceptual BIM acceptance model in FM based on the knowledge of experts and their experience with the topic. The proposed model combines the TAM2 and the PBC. The model consists of thirteen factors that are hypothesized to have direct or indirect effects on BIM acceptance. The primary contribution of this paper is to propose the foundation of research on the BIM challenge for FM as a guide for future research.

Building information models (BIM), through their rich digital information content, have created an opportunity to automate portions of the estimating, scheduling, and visualization processes in construction management. In this research, we are developing a method that applies rule-based spatial reasoning based on the topological relationships between the building components in a BIM to automatically generate a technologically and physically meaningful construction sequencing of the building components while automating association of these activities with BIM objects for purposes of 4D schedule visualization. The spatial reasoning takes into account considerations such as structural construction, material layers and work access, some common construction practices and hierarchical relationships between the building entities. The methodology is applied to the domain of commercial construction projects.

Manual regulatory compliance checking of construction projects is usually time-consuming and error-prone. There have been efforts both in academia and industry to automate this process. However, none of them achieved full automation. Specifically, the extraction of rules from regulatory text (e.g. building code) and its representation in a computer-processable format is still conducted manually or semi-automatically. Natural language processing (NLP) aims at enabling computers to process natural language text in a human-like manner. It provides basic concepts and methods for text processing and analysis, such as part of speech (POS) tagging, tokenization, sentence splitting, named entity recognition, and semantic role labeling, etc. This paper is intended to explore the effectiveness of utilizing syntactic (i.e. grammatical) and semantic (i.e. meaning descriptive) features of the text (using NLP tools and techniques) to automatically extract regulatory information from building codes. An automated information extraction (IE) approach - involving the use of IE rules - is proposed. Chapter 12 of the 2006 International Building Code was used to develop the IE rules, while Chapter 12 of the 2009 International Fire Code was used to test the approach. An overall F-measure of 0.94 shows the potential of the proposed approach. Based on the experimental results and their analysis, we conclude the paper by pinpointing possible ways for improving the proposed approach.

Nowadays, remote sensing technology allows for autonomous and remote data collection of construction resources. Data collected from various sources can be used to infer higher-level information about the entities being observed. This process, called data fusion, has been used in construction for tracking the location of material and equipment with a lack of studies on the use of data fusion for improving knowledge of workforce. This study explored the utilization of a data fusion approach for a continuous remote monitoring of construction workers' location and health. To this end, the authors deployed non-intrusive real-time worker location sensing (RTLS) and physiological status monitoring (PSM) technology, and later, used data fusion to analyze data from these devices.

Field managers are exposed to large amounts of information at the jobsite. Their ability to process this information is key to the success of construction operations in a project. In this paper, a method of cognitive analysis, known as Applied Cognitive Work Analysis, is used to document superintendents' work objectives and the information needed to attain such objectives. This is done with the purpose of improving the understanding of effective information use at the jobsite. Results from this type of studies are used to describe the aspects of work and their mutual relationships. Discussion on these results suggests the need for developing information tools that support specific instances of work.

Information technology adoption is critically important because it is a fundamental element of successful project management. Although some studies have been carried out to investigate the use of information technology in the construction industry, there is no comprehensive literature to compare the information technology adoption among different countries. This research aims at investigating the current extent of information technology use between developing and developed countries. To achieve this aim, a questionnaire was sent to 800 construction professionals from 20 countries. From those, 151 completed and reliable responses were selected to be analyzed. The result of the research reveals that there is no significant difference between developing and developed countries in information technology adoption; however, developed countries are more advanced in information technology use compared to developing countries. The results of this study are useful to provide directions in research, training, and development of strategies that will respond to the needs of the construction industry in the area of information technology selection.

This paper presents the conceptual framework by which we developed the Green Building Information Management System (GBIMS). GBIMS is a web-based client-server system designed to assist all project participants in accessing and retrieving information necessary for the planning and control of green building projects. Its schema includes two main components: project life cycle and information. The life cycle of a green building project was broken down into the three hierarchical levels of stages, processes, and activities using an adaptation of the OmniClass Construction Classification System. Important information concerning green building project management was compiled from the LEED rating system, including credits, project participants and their roles, certification documents, design and construction standards, and green materials. The design of GBIMS follows a three-tiered software architecture, which consists of three independent modules, namely, the user-interface module, the functional process logic module, and the data access and storage module. The relations among objects (entities) in GBIMS are illustrated through a class diagram. The GBIMS conceptual framework provides the foundation for the development of a comprehensive web-based green building project management system.

In order to perform a building energy analysis (BEA), BEA engineers collect and input various required data into energy analysis software programs. This step-by-step data input procedure is somewhat tedious because it can be done only sequentially through the data input user interfaces provided by energy analysis software programs. This paper introduces a method that enables the collection of concurrent data in parallel for BEA. To that end, we first categorized the required information into three types: general, architectural, and mechanical. Then, we developed the concurrent data collection process through analyzing the sources of these three types of information. The key technology of the concurrent data collection process is project temporary database (DB). This method will enable architects and engineers involved in a building project to input their data separately but concurrently. Consequently, this method will contribute toward increasing the efficiency of the data input process, and responsible parties will potentially be cleared on the process of building energy analysis.

Sharing research data is necessary for collaboration within a research network and is required by funding agencies, such as the National Science Foundation (NSF), that are enforcing the scientific method and ethics. However, methods and infrastructure for supporting construction research data management are currently underdeveloped; emphasizing the need for developing effective and efficient means for managing and sharing research data. A review of existing data management models reveals that there is currently no effective universal system for sharing the data obtained from construction research endeavours. This paper presents electronic product and process management systems (EPPMS) as a construction research data management and sharing approach. The proposed EPPMS is a web-based system, which utilizes workflows that can automate the collection, authorization, and dissemination of construction research data. A comparative analysis of the proposed system to the existing web-based cloud and web-based share point systems indicates that an EPPMS offers a more fitting solution for construction research data management.

Despite the transition from paper to digital media, hand-off of data and documents from construction to operations and facilities management is still cumbersome and often requires manual entry and duplication of effort. This paper presents initial findings from an ongoing pilot project that began in spring 2011 on a digital information exchange standard called COBie (Construction Operations Building Information Exchange). Through interviews with key participants, we analyze existing practices as well as proposed changes to be made to these practices. Across a large organization, digital information is not trusted—nor is information neutral. Information is connected to particular jurisdictions who currently control the creation and management of their own datasets. We found that despite availability of digital information, people generally prefer to obtain information from colleagues with direct knowledge of the project or from paper documents. Digital information was considered to be either too difficult to access or not viewed as trustworthy since digital data was not consistently maintained. As more digital information is amassed, including information from COBie and building information models, organizational cultures and practices need to be developed around these new datasets.

Bridge inspections are tedious, time consuming and complex tasks in the field which require highly specific information pertinent to the decisions at hand. Bridge inspectors assess the condition of bridge components based on standard rating guidelines and previous bridge inspection reports. Most bridge inspections are currently conducted manually with little support from Information Technology and the captured data must be manually entered into a computer system for later retrieval. Context-aware computing promises to make inspections more efficient by automatically associating captured data with bridge design data in a database. This paper presents a context-aware computing platform that facilitates bi-directional flow of information and supplements field inspectors with relevant data to support their operations. The implemented context-aware computing framework automatically interprets the spatial-context of the bridge inspector based on the inspector's position and head orientation. The framework also provides methods to map and store the geometric representation of the bridge-inspection elements in a database. To validate the framework, a context-aware computing application was designed. The application coordinates the inspector's spatial-context with the bridge model in the database so that the inspector is provided with data that is relevant to his/her context. The application also facilitates bi-directional communication between the inspector and the bridge inspection database management system. Finally, the characteristics of context-aware computing supported bridge inspection routines are compared against the traditional (manual) approach to bridge inspection routines.

Coordination is integral to operational efficiency of construction projects. Coordination process relies on managing dependent activities and the structural centrality in social networks is strategic to project actor's management activity. This study aims to explore the effects of network centrality on coordination performance. Network centrality concepts and coordination theory are examined via e-mail communication data of Ýstanbul Sabiha Gökçen International Airport's (ISGIA) New Terminal Building Wayfinding and Signage Design Project (WSDP) actors. E-mail data mining for identifying different coordination dependencies is derived from the constructs of Malone's (1988) coordination theory and used to measure the actors' coordination scores. Social network matrix of information exchange network is constructed to calculate degree, betweenness and closeness centrality measures. ISGIA data analysis suggests a significant relationship between out-degree, outcloseness centrality and coordination. Findings highlight that out- network centralities support the ability of an actor to coordinate the dependent actions of other project actors; and the design and construction practices rely on the central position in a network in mapping effective coordination processes.

Due to the recent economic downfall, the construction Industry has become a very competitive market. Overhead and profits are lower than ever. Thousands of construction companies are filing bankruptcy and closing their doors. As tough times fall upon the construction industry, construction companies have to become more innovative. Companies need to discover new ways to streamline their business. The larger firms have more resources to overcome this deficit, but the smaller companies are at a disadvantage. They have to find simple and inexpensive ways to become a more efficient business. This paper examines the implementation of cost-effective mobile application strategies in tougher economic times and analyzes how it is effectively being used by small and medium-sized companies in the construction industry. Two case studies will describe the benefits and limitations of these strategies and their impact on project performance. Mobile strategies implemented in these companies will be examined in relations with work process changes and cultural issues in order to analyze the direct and indirect benefits of the selected strategies. The author conducted interviews, on-site data collection, and document analysis. Simple and cost-effective strategies along with efficient management procedures and asset management tools allow small and medium-sized companies to realize an increase in office and jobsite efficiency, effectively saving time and cutting costs in order to compete in challenging times.

The healthcare industry is growing increasingly complex and providing a safe healthcare setting has become challenging for many healthcare facility managers. Most facility information is not linked to the healthcare delivery process, making it difficult to identify interactions and overlaps that may have critical implications for the smooth operation of the healthcare delivery process and patient safety. This inhibits the potential to capture real-time information that can facilitate timely interventions when hazardous situations develop. The impact of using real-time facilities information to ensure efficient healthcare operations has not been adequately studied. This paper is focused on an investigation of specific links and overlaps between facilities information and the healthcare delivery process. An understanding of the interactions between these two facets of healthcare delivery provides the healthcare industry a unique opportunity to enhance real-time decision-making thereby avoiding costly disruptions to the healthcare delivery process. The study presented in this paper involved a review of existing guidelines and standards for healthcare facilities management, interviews with key healthcare practitioners in a major hospital, and cognitive walkthroughs with the facilities management personnel. Based on the information obtained and the identification of typical facility failures, use cases were developed to determine synergies between facilities management and the healthcare delivery process, and to assess the potential for improvements from a patient safety perspective. The paper makes recommendations for improved use of real-time facilities information to support the healthcare delivery process.

With an increased emphasis on sustainable buildings, building owners have begun to demand better methods of predicting building system performance, in particular with respect to energy. A variety of energy modeling programs have been developed to meet the growing interest in energy efficient buildings. However, the energy modeling software is typically cumbersome to use and was designed to compare various system options for new construction. The retrofit sector of the building industry lacks a clearly defined energy auditing process and energy modeling tools developed specifically for retrofits. This research develops high level process models and the necessary information exchanges which can be utilized to develop a building typology tool for retrofit buildings. The study defines: (1) the need for a standard and transparent energy auditing process and modeling tools intended specifically for commercial retrofits; (2) typical vs. desired information flows (through an industry workshop) and a high level process model; and (3) initial criteria for a retrofit specific energy analysis methodology by determining which outputs and inputs are needed at the various stages to perform an accurate and useful energy assessment.

This study uses Vrijhoef and Koskela's model on the four roles of supply chain management (SCM) in construction to investigate how building information modeling (BIM) can be used in the management of construction supply chains. Two important facts are known about supply chains in general: 1. supply chains compete for projects, not isolated companies; and 2. participants who can see each other's needs are able to better manage their business and ultimately better serve their clients. In this environment, BIM may be used as a catalyst to provide visibility in terms of product, project, and participants' requirements to the extended supply chain working to deliver a project. The authors identify cases provided by the literature and ongoing case studies in which BIM has been utilized to exchange information with suppliers. The cases are categorized using the model to identify which SCM roles are currently being used for different products based not only on the characteristics of the products but also the supplier's approach to delivering product and services. The findings point out the supply chain decisions that were enabled by BIM as well as opportunities for further application of models to facilitate the implementation of supply chain practices in construction.

The existing machine vision-based 3D reconstruction software programs provide a promising low-cost and in some cases automatic solution for infrastructure as-built documentation. However in several steps of the reconstruction process, they only rely on detecting and matching corner-like features in multiple views of a scene. Therefore, in infrastructure scenes which include uniform materials and poorly textured surfaces, these programs fail with high probabilities due to lack of feature points. Moreover, except few programs that generate dense 3D models through significantly time-consuming algorithms, most of them only provide a sparse reconstruction which does not necessarily include required points such as corners or edges; hence these points have to be manually matched across different views that could make the process considerably laborious. To address these limitations, this paper presents a video-based as-built documentation method that automatically builds detailed 3D maps of a scene by aligning edge points between video frames. Compared to corner-like features, edge points are far more plentiful even in untextured scenes and often carry important semantic associations. The method has been tested for poorly textured infrastructure scenes and the results indicate that a combination of edge and corner-like features would allow dealing with a broader range of scenes.

Building information modeling (BIM) is an emerging technology and process that provides rich and intelligent design information models of a facility, enabling enhanced communication, coordination, analysis, and quality control throughout all phases of a building project. Although there are many documented benefits of BIM for construction, identifying essential construction-specific information out of a BIM in an efficient and meaningful way is still a challenging task. This paper presents a framework that combines feature-based modeling and query processing to leverage BIM for construction. The feature-based modeling representation implemented enriches a BIM by representing construction-specific design features relevant to different construction management (CM) functions. The query processing implemented allows for increased flexibility to specify queries and rapidly generate the desired view from a given BIM according to the varied requirements of a specific practitioner or domain. Central to the framework is the formalization of construction domain knowledge in the form of a feature ontology and query specifications. The implementation of our framework enables the automatic extraction and querying of a wide-range of design conditions that are relevant to construction practitioners. The validation studies conducted demonstrate that our approach is significantly more effective than existing solutions. The research described in this paper has the potential to improve the efficiency and effectiveness of decision-making processes in different CM functions.

This paper presents a comparative study of commercially available BIM-based estimating software, and an investigation of the changes in work practices and workflows incurred by the adoption of such software by a construction company. Due to the fragmentation of the construction industry and the linearity of the design process, cost estimating is typically performed at a time when the conceptual design is quite advanced or even completed, which is much too late in the design process to help the different stakeholders make informed decisions. Performing value engineering and cost estimation from the beginning of the design process would potentially enable a faster and more cost-effective project delivery process, higher quality buildings, and increased control and predictability for the owner. This research examines the changes in work practices and work flows within a construction company as they move towards adopting Building information Model (BIM) estimating process. To conduct this research, we: (1) tested several BIM-based cost estimating software tools to support different phases of design, (2) evaluated the benefits and challenges of working with this software, and (3) analyzed the work practices and workflows of a BIM-based estimating process within the firm. Finally, we propose a multi-stage technology adoption scenario.

Recording the continuous location of equipment and workers with Global Positioning System (GPS) units can contribute in the analysis of how safely a construction site operates. Automated data gathering and analysis for safety become even more valuable when reliable methods exist that record and report events that otherwise would not be recorded because they are labor intensive in observation or prone to human error in judgment. This paper presents a new safety approach that features automated analysis of continuously collected proximity data between construction workers, heavy construction equipment, and hazardous construction spaces in outdoor construction environment. We recorded field data using small GPS units that were mounted on construction helmets or attached to construction equipment. This paper first evaluates the performance of the technology that was used to gather continuous location data to construction resources (workers and equipment). It then explains how the generated spatio-temporal information can be communicated to decision makers so it improves the safety performance of workers near equipment or other hazards. The results that are presented include a case study to outdoor construction environment. It demonstrates how potential users can measure the safety performance of construction resources (workers, equipment) automatically and use the generated information as new knowledge in safety training and education.

Building projects have a great impact on stakeholder values such as economy, safety, sustainability, urban aesthetics, etc. However, there is neither a formal model for assessing values (what is of worth, merit, utility, or importance to project stakeholders) nor an automated system for measuring how values are impacted by our planning and design decisions. As such, there is a need for a semantic model for values and value measurement. This entails: (1) discovering the values that are significantly impacted by building projects, (2) identifying how to measure the value of buildings to its stakeholders based on those values, (3) integrating such value data with the Building Information Model (BIM) so it becomes part of a dynamic building data/information model throughout the building's life cycle. This paper discusses value discovery and provides a brief overview of a proposed formal, axiological value assessment model and its integration with BIM. The paper also presents a case study about assessing safety values in educational buildings.

Construction site is rugged, dynamic, and complex, involving a large number of objects that continuously change their locations and occupied spaces. Being able to accurately locate site objects and track site dynamics is critical to project control. Automated locating technologies such as Radio Frequency Identification (RFID) have proven to be beneficial in tracking some construction site objects. The biggest challenge in applying the RFID technology is that the received signal strength (RSS) varies over time and location, and there is no direct relationship between signal strength and detection range, leading to low positional accuracies in the estimated tag locations. This paper presents an algorithm termed BConTri that combines a "boundary condition method" and the trilateration concept to estimate tag location in three-dimensional (3D) real world coordinates from four or more RFID readers equipped with GPS. A comprehensive assessment of the positional accuracy was applied to field experiment results and a high accuracy of the algorithm was observed. A measure of the spatial dilution of reader distribution was proposed, which has a linear relationship with the resulting accuracy of the estimated tag location. This could help in estimating the accuracy and quality control of RFID-based locating and tracking systems in construction.

Construction site is rugged, dynamic, and complex, involving large number of resources that intensively interact with each other with varying site activities. Being able to precisely locate, and track the site dynamics is critical to project management. Studies have explored the potential of the Radio Frequency Identification (RFID) technology in estimating the two-dimensional (2D) and three-dimensional (3D) locations of construction site objects at discrete time points. Information systems based on the RFID technology have emerged to assist decision-making in construction project management tasks. However, for the purpose of tracking the construction site dynamics, both capabilities of estimating the 2D and 3D locations of site objects at discrete time points and tracking the real-time movement of site objects must be incorporated in the tracking system, leading to a four-dimensional (4D) system. This paper presents the framework of a 4D tracking system to continuously track the 4D status of construction site dynamics. The framework consists of RFID, global positioning system (GPS) wireless sensor network and geographical information system (GIS). A prototype system was implemented based on the 4D framework and tested in a field experiment to verify the system implementation.

In the U.S., 40% of the energy consumption is from buildings, approximately 48% of which is consumed by heating, ventilation, and air conditioning (HVAC) systems. Implementing demand driven HVAC operations is a way to reduce HVAC related energy consumption, and ultimately to achieve sustainable building operations and maintenance. This relies on the availability of occupancy information, which determines peak/off-hour modes and impacts cooling/heating loads of HVAC systems. This research proposes an occupancy monitoring system that is built on a combination of non-intrusive sensors that can detect indoor temperature, humidity, CO2 concentration, door status, light, sound and motion. The effectiveness of each sensor in occupancy estimation is evaluated. The sensor data is communicated wirelessly, and processed in real time using a back-propagation (BP) artificial neural network (ANN) algorithm. Field tests are carried out in a lab space that is shared by up to 9 people for 15 consecutive days. The test results report an overall detection rate of over 90%, which indicates the ability of the proposed system to monitor the occupancy information of multi-occupancy spaces in real time in support of demand driven HVAC operations.

In recent years, many researchers have investigated automated progress tracking for construction projects. These efforts range from 2D photo feature extraction to 3D laser scanners and Radio Frequency Identification (RFID) tags. A multi-sensor data fusion model that would utilize multiple sources of information would provide a better alternative than a single-source model for tracking project progress. However, the existing fusion models are based on data fusion at the sensor and object levels, and therefore, are incapable of capturing critical information regarding non-structural trades and activities on a construction site, such as welding, inspection and installation activities. This paper presents an activity-based data fusion model, which incorporates an Ultra Wide Band (UWB) positioning system to track activities in a construction project. A field experimentation study on an industrial-type building construction project was conducted to validate the model presented in this research. The scope of the experimental program was limited to ductwork, HVAC, and piping activities on the project, but the model, experiments, and results are scalable to a complete construction project. A comparison of concrete, steel, and piping projects showed that for piping projects, where the asbuilt environment may be substantially different than as-designed models, the activity-based progress estimation model of this paper can be fused with existing object-based models to provide a more accurate and reliable progress estimate.

Sensing and site data acquisition are active areas of research for the construction engineering and management domain. A number of research initiatives around the globe are focused on novel sensing applications for managing site safety, productivity improvements, progress monitoring, site layout planning, and for innovative approaches to supply chain management. Time of Flight cameras and laser scanners are the tools of choice for real time and near real time decision making on jobsites. However, most of these applications are limited to academic research and limited field trials have been carried out. A number of operational decisions are necessary before sensing equipment can be deployed. These decisions are challenging for companies and researchers alike as there is limited test data available regarding the performance characteristics for the various equipment options. This paper reports on the performance of Xbox Kinect Sensors for spatial modeling on construction sites. Designed experiments were conducted to characterize the accuracy and resolution of Xbox Kinect sensors as well as the interference between multiple Xbox Kinect sensors. The experiments provided quantitative knowledge about the performance of XBOX Kinect sensors in terms of spatial modeling, therefore establishing a baseline for Kinect performance expectations in similar modeling applications.

The image processing based human recognition is yet a challenging task because of series of complications such as variations in pose, lighting conditions and complexity of background in the tracking environment. This study introduces a novel methodology to track construction workers using image processing techniques and depth information generated from the Microsoft Kinect sensor. Kinect is a new game controller technology introduced by Microsoft in November 2010. This automated real-time worker tracking system provides an opportunity to track the construction worker location and their movements in a specified indoor work area. The research study proposes a properly color coded "construction hardhat" as a key tracking object which can be used to differentiate site personnel (worker, supervisor, engineer, etc.). The proposed method detects construction workers in three major stages which includes human recognition, hardhat recognition and 3D localization. The human recognition is done by analysing human body parts. 3D positions of body joints are accurately predicted from a single depth image. The construction hardhat detection is based on characteristics of the hardhat such as unique shape and color. Template based template matching is used as the pattern recognition technique.

The need of sustainable urbanization drives construction engineers to explore the underground space to improve quality of life, meet with the challenges of population growth, and satisfy increasing infrastructure demands for utility pipelines and subways. However, unexpected obstructions or heterogeneous ground conditions make underground construction a risky operation, increasing construction cost while presenting additional safety hazards. Examples include (1) high pressure underground water stops a tunnel boring machine (TBM); (2) breaking an existing water main leads to flooding the downtown area; and (3) hitting an unexpected gas line causes an explosion. To a certain extent, all of those accidents can be attributable to the lack of cost-effective technology for detecting buried underground obstacles. The current practices such as geotechnical test holes and ground penetration radars (GPR) have their limitations in revealing underground situations. Meanwhile, the emerging technology of ultra-wide band (UWB) radar holds the potential to provide a cost-effective, non-destructive detection method. In this paper, a critical review of current practices and established methodologies is given. The functionality, working mechanism and application potential of UWB radar technologies in underground construction are described. Preliminary lab testing results are presented. Research findings are summarized and further research plans are discussed in conclusions.

In this paper we present a novel method for reliable recognition of construction workers and their actions using color and depth data from a Microsoft Kinect sensor. Our algorithm is based on machine learning techniques, in which meaningful visual features are extracted based on the estimated body pose of workers. We adopt a bag-of-poses representation for worker actions and combine it with powerful discriminative classifiers to achieve accurate action recognition. The discriminative framework is able to focus on the visual aspects that are distinctive and can detect and recognize actions from different workers. We train and test our algorithm by using 80 videos from four workers involved in five drywall related construction activities. These videos were all collected from drywall construction activities inside of an under construction dining hall facility. The proposed algorithm is further validated by recognizing the actions of a construction worker that was never seen before in the training dataset. Experimental results show that our method achieves an average precision of 85.28 percent. The results reflect the promise of the proposed method for automated assessment of craftsmen productivity, safety, and occupational health at indoor environments.

Video recording of construction operations provides an understandable data that could be used to analyze and improve construction performance. Despite the benefits, manual stopwatch study of previously recorded videos can be labor-intensive, may suffer from biases of the observers, and impractical after substantial period of observations. To address these limitations, this paper presents a new vision-based method for automated action recognition of construction equipment from different camera viewpoints. This is particularly a challenging task as construction equipment can be partially occluded and they usually come in wide variety of sizes and appearances. The scale and pose of the equipment action can also significantly vary based on the camera configurations. In the proposed method, first a video is represented as a collection of spatio-temporal features by extracting space-time interest points and describing each feature with a histogram of oriented gradients (HOG). The algorithm automatically learns the probability distributions of the spatio-temporal features and action categories using a multiple binary Support Vector Machine (SVM) classifier. This strategy handles noisy feature points arisen from typical dynamic backgrounds. Given a novel video sequence, the multiple binary SVM classifier recognizes and localizes multiple equipment actions in long and dynamic video sequences containing multiple equipment actions. We have exhaustively tested our algorithm on 1,200 videos from earthmoving operations. Results with average accuracy of 85% across all categories of equipment actions reflect the promise of the proposed method for automated performance monitoring.

Limited resources are available to timely inspect and maintain the aging civil infrastructure across the United States. Reality capturing technologies, such as laser scanning, is replacing visual inspection and manual surveying for improved data qualities and reduced resource requirements, while bringing challenges of timely processing terabytes of spatial data. Even using state-of-art 3D reverse engineering environments, inspectors need to manually select data processing algorithms, compose and configure data processing workflows, and verify the correctness of these workflows. Such manual design and execution of spatial data processing workflows are tedious, and result in sub-optimal workflows that do not fully utilize time and resources for producing accurate and detailed spatial information needed by domain applications. This paper proposes a computational framework that will assist in the infrastructure inspection process through streamlined spatial data processing workflow generation, execution, and optimization. Based on previous studies on spatial information query, spatial data processing, and building information modeling (BIM), the authors are exploring the feasibility of automatically generating and optimizing spatial data processing workflows based on formalized representations of these workflows.

Airborne Light Detection and Ranging (LIDAR) data is used for multiple applications, such as urban planning, emergency response, flood control, and city 3D reconstruction. The LIDAR data in its raw form needs to be classified for the above applications. There are two types of classifications: binary and multi-class. In the binary classification, the given LIDAR data is classified into two classes: terrain or non-terrain. In the multi-class classification, the given data is classified into multiple classes, such as ground, vegetation (low, medium, and high), and buildings. Although different techniques have been developed to address the challenges in LIDAR data applications in the last two decades, no single algorithm gives the best result. In this paper, we presented two Ensemble methods (Bagging and AdaBoost) that combine multiple algorithms in an intelligent way. These methods were developed and evaluated using 100 decision trees as the weak classifiers and combination of both point and neighborhood features. The authors were able to achieve the accuracy up to 98.9% for the binary classification and 94.6% for the multi-class classification. While AdaBoost performed slightly better that Bagging, the Bagging was more resistant to over-fitting.

Work sampling has been accepted as a valuable method for assessing the productivity of workforce in construction sites. It helps in identifying the problem areas and gives direction for productivity improvement programmes. But, observing and categorizing work activities is a tedious and difficult task in work sampling assignment. Video-based methods have been investigated as an alternative for human observation, but their performance in classifying worker activities is severely affected by the harsh construction site environment. Preliminary studies have shown that accelerometer data carry rich information pertaining to movement characteristics of workers and hence can be used classifying worker activities. The present study is an extension to this, investigating accelerometer based method for classifying bricklaying activities. The data collection was performed on five bricklayers with tri-axial accelerometer data loggers attached to the right left lower arm, the left lower arm and the waist, during their normal course of work. Video recordings of the worker activities were simultaneously carried out to serve as the ground truth. The accelerometer data was subjected to preprocessing and also trained with multilayer perceptron classifier algorithm for worker activity classification. The results show that the accelerometer-based classifier gave an overall accuracy of 81.37% while classifying bricklaying activities into classes of effective, contributory and ineffective categories.

Image-based (i.e., photo/videogrammetry) and time-of-flight-based (i.e., laser scanning) technologies are typically used to collect spatial data of infrastructure. In order to help architecture, engineering, and construction (AEC) industries make cost-effective decisions in selecting between these two technologies with respect to their settings, this paper makes an attempt to measure the accuracy, quality, time efficiency, and cost of applying image-based and time-of-flight-based technologies to conduct as-built 3D reconstruction of infrastructure. In this paper, a novel comparison method is proposed, and preliminary experiments are conducted. The results reveal that if the accuracy and quality level desired for a particular application is not high (i.e., error < 10 cm, and completeness rate > 80%), image-based technologies constitute a good alternative for time-of-flight-based technologies and significantly reduce the time and cost needed for collecting the data on site.

Vision based tracking can provide the spatial location of construction entities such as equipment, workers, and materials in large scale, congested construction sites. It tracks entities in video streams by inferring their locations based on the entities' visual features and motion histories. To initiate the process, it is necessary to determine the pixel areas corresponding to the construction entities to be tracked in the following consecutive video frames. In order to fully automate the process, an automated way of initialization is needed. This paper presents the method for construction worker detection which can automatically recognize and localize construction workers in video frames. The method first finds the foreground areas of moving objects using a background subtraction method. Within these foreground areas, construction workers are recognized based on the histogram of oriented gradients (HOG) and histogram of the HSV colors. HOG's have proved to work effectively for detection of people, and the histogram of HSV colors helps differentiate between pedestrians and construction workers wearing safety vests. Preliminary experiments show that the proposed method has the potential to automate the initialization process of vision based tracking.

Several tasks in the Architectural, Engineering, Construction and Facility Management (AEC&FM) domain require real-time geospatial information. Traditional measurement methods are widely being replaced by more advanced technologies. 3D laser scanners are increasingly being used for diverse tasks during the lifecycle of a facility. However, a variety of process, environmental, scanner and analysis related factors can affect the quality of laser scanned data. Error sources, particularly those inherent in early stages of the laser scanning process, have not been well-addressed. This paper focuses on the effects of such error sources on the quality of the raw/processed data. Lessons learned through the planning, laser scanning and data processing of a facility are shared. The dataset consists of a total of 68 scans from both indoor and outdoor environments collected through using two different types of scanners. The effects of pre-scan site visits and proactive planning on reducing the consequences of different error sources are illustrated through examples. Lessons learned emphasize the need for formalization of the planning stage of laser scanning process, and data collection approaches for the AEC&FM domain applications, to enhance the quality of the raw/processed data.

This paper presents a new image-based approach for 3D mapping the locations of the rebar and embedded components in a railway bridge deck prior to placement of concrete. Our approach enables practitioners to quickly and automatically identify where the rebar and other underlying components are within the bridge decks, locate safe and unsafe drilling area, and create a valuable documentation for future retrofit or rehabilitation of the concrete bridge decks. In the proposed method, digital images collected along the rebar cage prior to placement of concrete are processed to automatically generate a 3D point cloud. Using a set of control points, the reconstructed point cloud is transformed into the site coordinate system. Next, a pattern recognition algorithm identifies the rebar locations. A cellbased map of the underlying structure is generated and the occupancies of the cells are automatically detected and visualized using color. Impact of the number of images and control points on the accuracy and density of the image-based 3D reconstruction, registration, and automated recognition of the rebar locations and safe/unsafe cells are studied in detail. Results of our experiments show the promise of applying this low-cost approach in practice.

Historically the construction industry has taken a conservative approach to using new technologies; however there is increasing demand from both public and private sector to enhance roadway maintenance operation productivity using a telematics technology. The term telematics literally means any integrated use of wireless telecommunication and informatics. Telematics collect and transmit various real time data from remotely deployed equipment to a centrally integrated database system through various wireless systems. The use of telematics technology is a way to not only assess existing equipment productivity but also provide a baseline for future productivity improvement, optimizing operation planning, and establishing long-term strategic organization. Operation managers will potentially achieve various benefits such as more effective and efficient equipment operation in a wider area, flexibility and resiliency of operation planning, and, eventually, financial benefits from the ability to use smaller maintenance equipment fleets. The paper presents 1) details of telematics technology, and a suggested application plan for telematics data collection system implementation, 2) information on raw data integration and productivity data analysis for development of a fleet management metrics to identify areas of improvement.

The United States construction industry experienced 151 fatalities resulting from workers colliding with objects and equipment in 2009. These fatalities accounted for approximately 18% of the total construction fatalities and 3% of the total workplace fatalities experienced that year. Construction workers and equipment are often required to function at close proximity on construction jobsites. This paper evaluates the effectiveness of emerging radio frequency (RF) remote sensing technology that can promote safety in construction by providing real-time alerts for worker-on-foot and construction equipment operators when a potentially hazardous proximity situation exists. Numerous experiments designed to emulate typical interactions between workers-on-foot and construction equipment, including installing proximity sensing devices on actual construction equipment, were used to evaluate the proximity sensing technology. Results from the experiments indicate that real-time pro-active proximity sensing and warning technology can promote safety on construction jobsites.

Rapid energy modeling is a streamlined process to capture, model, and analyze building energy performance. Timely assessment of existing building energy performance helps owners and facility managers to identify potential areas for better retrofit, and meet environmental and economic goals. Despite the increasing attention to building energy performance, the current process of energy data collection and modeling is time-consuming and requires certain level of expertise. In order to facilitate the process, this paper presents a new approach for actual energy performance modeling of existing buildings using digital and thermal imagery. First, using an image-based 3D reconstruction pipeline which consists of Structure-from- Motion, Multi-View Stereo, and Voxel Coloring/Labeling, the current geometrical condition of a building is captured. Subsequently, using a new 3D thermal modeling algorithm, a dense thermal point cloud model of the existing building is reconstructed in 3D. Finally, the reconstructed 3D building and thermal models are automatically superimposed within a single environment. Within the resulting 3D spatio-thermal point cloud model, temperature values can be queried and visualized at point level. The proposed method is validated on several rooms in an existing instructional facility. The underlying modeling process, and the potential benefits from converting digital and thermal imagery into ubiquitous sensors and reporters of building energy use are discussed in detail.

Work related fatigue and injuries are critical issues in the construction industry. Repetitive and physically demanding nature of the activities and awkward work postures are the primary reasons for work related fatigues and injuries. In view of this, worker training on ergonomics is necessary before the start of any construction activity. Traditional methods of worker monitoring are tedious and in efficient. Recent approaches to understand worker ergonomics use specialized devices to physically monitor the health of workers. In addition to this, attempts have been made to use computer vision techniques to understand workers ergonomics; however they mostly focus on estimating the posture of workers. In this research, we present a framework for integrating posture analysis of workers and a predefined set of rules to categorize work tasks as ergonomic or non-ergonomic.

This paper presents an automated methodology for tracking earthmoving operations in near real time utilizing RFID technology to capture data during construction. It is based on attaching low cost passive RFID tags to hauling units (trucks) and attaching fixed RFID readers to designated gates of projects' dump areas. The RFID readers will identify and record the time each truck enters or exits one of these gates. The captured data will then be transferred wirelessly from the RFID reader to a computer housed in one of the temporary offices onsite and to the main server in contractor's head office. The collected data will be analyzed and processed automatically, without human intervention, to calculate the productivity of the hauling unit and report it directly to onsite personnel. Database application is developed to implement and automate the developed methodology in Microsoft Access. The developed database is used to process the data captured by the RFID-based system to calculate earthmoving productivity in near-real-time. It can also be used in estimating productivity of similar works during planning stage. The developed methodology is expected to facilitate early detection of discrepancies between actual and planned performances and supports project managers in taking timely corrective measures.

A challenge of using terrestrial laser scanners on jobsites is to effectively plan the scanning locations and configure scanners' technical parameters according to the domain requirements and site conditions. With time limits in the field, it is challenging to manually design and analyze scanning plans considering technical capabilities of scanners and environmental conditions (e.g., occlusions) for ensuring that all needed spatial information is captured with the required levels of accuracy and detail. In addition, the information requirements of construction tasks may vary spatially and temporally, further complicating the scan planning. These facts can lead to longer data collection time, unexpected interferences on jobsites, and missing data. This paper proposes an approach of automated laser scan planning based on sensor models of terrestrial laser scanners. We developed a sensor model capturing the relationships between various data collection parameters (e.g., data collection distances) and data quality metrics (e.g., accuracies and densities of 3D point clouds). Given the user-specified data quality requirements, an optimization algorithm can use this sensor model to identify scanning plans that minimize the data collection time while optimizing the data qualities and spatial information coverage.

Workers' unsafe actions are likely to result in injuries and are regarded as precursors of incidents. Behavior measurement can thus be used to evaluate safety performance and prevent serious accidents. However, the time-consuming task involved in field observation has made it difficult to monitor workers' behavior on a jobsite. To address this limitation, this paper introduces vision-based motion capture techniques to detect unsafe actions in site videos. First, prior models representing unsafe actions are collected through experiments and used to identify similar actions in site videos. Then, 3D human skeleton models are extracted from these videos, and both these skeleton models and prior models are transformed onto the same space for motion detection. As a case study, motion data for actions during ladder-climbing are collected and tested. The result reveals that the proposed approach may work well for detecting particular actions with motion data.

Automated control of production lines in different segments of manufacturing has been advanced due to emergence of sensing devices and the repetitive character of the processes. The construction industry, however, still suffers from inefficiencies in real-time control of activities due to the manual practice of monitoring, and the fragmented and temporary nature of construction projects. Several sensing technologies including computer vision-based systems have been introduced to address this issue on construction sites. Earthmoving projects are one of the most suitable areas to employ vision-based techniques to extract productivity data because it is possible to select clear sightlines and earthmoving equipment are relatively easy to recognize. In addition to challenges of developing efficient object detection and tracking algorithms, activity recognition based on collected data from detection and tracking engines is yet to be tackled. In this paper, a logical framework is introduced that combines object recognition, tracking, and rational events to recognize dirt loading to a dump truck by a hydraulic excavators, and measure the working cycles and idle times of the earthmoving plants. This logical algorithm showed promising performance in which the variations were caused by deficiencies of recognition and tracking engines rather than the activity recognition algorithm.

The national infrastructure system is at a crossroads with a need for renewal and expansion in the most efficient manner possible. Light railway construction requires the installation of embedments in reinforced concrete pavement along the length of elevated sections of the railway system. Conventionally, wooden dowels are manually placed into the reinforcing steel mat before concrete placement to form the slot for the embedments; however this is labor intensive and can yield inconsistent spacing. An alternative method is digitally mapping the locations of the reinforcing steel-free space prior to concrete placement to identify where holes could be drilled without hitting the steel reinforcement. The challenge is avoiding impacting production. Using field-based data, this study identifies the number of hours to create the map without impacting production for a typical railway section. Discrete event simulation (DES) modeling is utilized to conduct the analysis. To substitute the alternative method, scanning a typical railway section falls within the capabilities of most laser scanning technologies; however, the processing of images to create a useable model controls. This research demonstrates a case study of applying DES to analyze productivity impacts on a repetitive process and investigates the capabilities of 3D imaging technologies for effective field use.

Construction projects are characterized by their dynamic nature and operational details. This paper presents a hybrid simulation methodology; designed to model construction projects. The methodology utilizes Discrete Event Simulation (DES) and System Dynamics (SD). DES has been widely used in modeling construction operations; however, it lacks the ability to model the global aspects of operations being modeled and the cause-effect relations of simulation variables. SD is utilized to circumvent these limitations. Both simulation methods provide valuable decision support but none is individually capable of capturing the holistic nature of the operation being modeled. The developed methodology integrates DES and SD to utilize their respective advantages in simulating construction operations. The developed methodology encompasses five stages: 1) identification of model objectives, 2) decision criteria to assist in selecting simulation methodology, 3) building simulation model and identification of interface variables, 4) computation framework and 5) implementation and testing. The paper describes the essential features of the developed methodology and its computational framework and focuses primarily on the modeling aspects of SD. A case study project is analyzed to demonstrate the use of the developed methodology and to highlight its capabilities.

The logistics for the supply of tires for trucks utilized in mining operations are generally affected by their demand and supply on the market. In times of high demand and tire scarcity, operations of most companies with large truck fleets are affected due to inadequate analysis and tire usage planning. The lack of a proper tool for practitioners to use for this purpose has contributed to the problem. This study proposes a special purpose simulation template that can be used to solve the problem. The template was developed for analyzing a six tire truck because it is the most common truck type used in mining operations. It utilizes statistical distributions fitted to historic field data of tire usage, and outputs the most likely number of used, early failed and worn out tires for the analyzed period. A simulation based approach was adapted because of the dynamic and random nature of the tire usage problem which does not lend itself to analytical solutions.

Factory based (modular and panelized) building methods have been applied to a high proportion of construction projects due to their reduced waste, limited environmental impact, and decreased cost and construction times. Redesigning the production process, facility layout, and material handling process can thus improve productivity and reduce costs for manufacturers. Virtual Reality (VR) is increasingly being used to investigate the best methods for balancing the flow of construction activities and optimizing resources to prevent costly on-site errors. This tool can be applied in planning and designing module systems in manufacturing production lines to promote healthy, safe, and productive working conditions by reducing workers' fatigue and injuries, and their associated costs. This paper identifies and quantifies work-related ergonomic hazards from residential construction floor panel framing activities, using the VR model of the construction process to replace onsite observation and an ergonomic assessment based on ErgoCheck, a comprehensive ergonomic rating and assessment framework. The VR model uses an internal timer for productivity (cycle time) assessment. The impact of the ergonomic interventions on work productivity is thus assessed and the results show the potential of ergonomic interventions in improving production line productivity through a reduction in idle and cycle time.

Critical Path Method (CPM) is the most widely used project scheduling tool. However, CPM tools are limited as a project management method as they cannot be used to track and update the schedule as construction progresses. Often, during construction, activities are interrupted due to impacts of uncertain events like severe weather and unforeseen harsh geological conditions, resulting in altered critical paths. From a project management perspective, this means that given uncertain conditions, some non-critical activities have a likelihood of becoming critical during the project execution and vice versa. Therefore, the objective of this paper is to identify the changes of activities' criticality during the construction process. It is assumed that an activity's probability of being critical tends to be stable during the construction given a construction management strategy. The critical path segment (CPS) technique and interactive simulation are coupled to capture the changes in an activity's criticality for a given strategy. The research uses the CPS technique to schedule and simulate a highway reconstruction project repeatedly using different strategies. For each simulation trial, the changes in the critical path are recorded to identify the criticality of each segment. The significance of this research is that it applies the CPS technique within a dynamic environment and presents a general method to predict the likelihood of an activity becoming critical during the construction process.

Construction sites are vulnerable to natural and manmade disasters that impose direct threat to contractor employers. High-rise building projects are more critical in such emergency situations because of the need to evacuate a large number of laborers who are working on the different floors of the building. Occupational safety regulations require general contractors to establish employee emergency action plans that specify emergency evacuation procedures and escape route assignments. These emergency plans are usually evaluated and practiced using real life drills, which face some critical challenges related to egress practicality and changing construction environment, especially in high-rise building construction sites. To overcome these challenges, this paper presents a conceptual agent-based simulation framework that would support general contractors in evaluating labour emergency evacuation plans in high-rise building construction projects. The framework is designed to facilitate: 1) modelling of construction activities workspaces that represent the number and locations of activities crews; 2) representing labour egress behaviour using software autonomous agents; 3) modelling of the physical space and evacuation routes of the building; and 4) evaluating the performance of emergency action plans. The proposed framework should prove useful to general contractors and public safety officials in effectively analyzing emergency action plans.

Building Information Modeling realm is expanding with the advent of new technologies, processes and software for Architecture, Engineering, Construction and Facility Management industry. The importance of robust knowledge sharing between different stakeholders in a project is of highest priority in such scenarios. model diew definitions provides an empirical specification for the implementation of the Industry Foundation Class (IFC) schema by software companies. The objective of this research is to create an ontological framework, which makes the IFC definitions more formal and consistent. A formal specification of IFC entities to create taxonomy of classes and subclasses between them is adopted for this research. Such an approach will make model view specifications unambiguous and reusable thereby reducing the development time of model views. The precast/pre-stressed concrete industry is selected as the domain for the ontology definitions. Case studies developed illustrating the exchange of a fabrication model between architect/engineer, precast detailer and fabricator shows the feasibility of this approach. The outcome of this research provides the mechanism for applications such as modular MVDs, smart and complex querying of building models, making data sharing across applications simpler with limited rework.

In any construction project, site layout planning (SLP) is a critical step that maximizes the efficiency in executing different project activities. The allocation of different facilities on site is often a complicated problem that requires extensive effort in computer modeling and long processing time to find the optimum solution. The main objective of a SLP problem is minimizing the travel distance between facilities and material handling, which in turn minimizes the overall time and cost of executing the project. The SLP is a cumbersome problem as it is classified as an NP-hard problem that belongs to the class of dynamic optimization. This paper presents the testing and the application of a newly developed evolutionary algorithm - named Electimize- in solving NP-hard dynamic optimization problems in construction engineering. Electimize simulates the phenomenon of the electric current conduction through the flow of electrons in the branches of the electric circuit. The basic advantage of Electimize over other evolutionary algorithms (EAs) lies in its ability to evaluate the quality of each value in the solution string independently. This paper primarily focuses on: 1) The basic steps of optimization using Electimize; 2) SLP problem modeling using Electimize; and 3) Testing the capability of the Electimize in solving NP-hard dynamic optimization problem in construction engineering. Electimize was applied to a benchmark SLP problem from the literature. The problem was attempted in the past using mathematical techniques, and evolutionary algorithms. The results showed that Electimize outperformed other algorithms by identifying a new optimal site layout of the facilities of the problem.

Current applications of BIM in the architecture, engineering and construction (AEC) industry are primarily limited to presentational purposes for clients, design clash detection, walk-through simulations, 4D animations, and on-site construction coordination. This paper examines the use of BIM as a platform to perform labor productivity studies considering alternative construction methods. This research exploits the CIS/2-standarded steel structural information within existing steel BIM and integrates the model with a unit rate labor productivity and material attributes database to perform an evaluation of the productivity impact of using quick connection steel systems on a typical industrial project. The results of analyses show that the proposed steel connection system used 38% fewer work hours than conventional steel connection (bolt and weld) systems did on the model project. The impact of the proposed construction method on the model project's schedule performance and work packages both before and after adopting the innovation were presented.

Placing embeds into reinforced concrete structures, after concrete is poured, without damaging reinforcement bars (rebar) is an industry-wide challenge encountered across the construction industry. In concrete structures such as containment vessels, bridge decks and post-tensioned concrete floors damaging rebar may compromise structural integrity and result in considerable rework. Although negative impressions for embeds can be made by placing various objects such as wooden dowels or steel rods into the rebar cage prior to pouring the concrete (and removing them once the concrete has partially or fully set), this practice is labor intensive and time consuming. A method of mapping the locations of the rebar free spaces before pouring and controlling the drilling process in real-time could have significant benefits. This paper presents research that investigated and implemented conceptual solutions for processing and incorporating point cloud data obtained from various 3D-imaging technologies into the drilling process. The 3D imaging technologies were used to map the locations of rebar within a replica of a section of a railway bridge deck. Once the point clouds were processed, zones that are safe for drilling are automatically detected and saved as a Building Information Model (BIM) that is then used to provide real-time feedback to the drill operator about whether it is safe to continue drilling based on the position and orientation of the drill. A conceptual method for providing visual feedback about the rebar-free zones to the drill operator using a laser projector was also developed. Finally, a visualization method for comparing the data obtained from the various 3D imaging technologies using the BIM is discussed.

Existing buildings now represents the greatest opportunity to improve building energy efficiency. Building energy performance (BEP) analysis is becoming increasingly important because decision makers can have a better visualization of their building's performance and quickly make the solution for improving building energy efficiency and reducing environmental impacts. Nowadays, it is a common practice to obtain point clouds of existing buildings through using 3D laser scanning technology for as-is building modeling. However, current methods need manual process to convert the point clouds into a building information model which is very time consuming and labor intensive. Therefore, the objective of this paper is to introduce a methodology that automatically recognizes the major components of the building envelope as individual objects from point clouds for energy simulation. In this paper, methodology of recognizing different building envelope components is introduced. Additionally, a field test on a residential house was made to validate the proposed algorithm, and in the test results it shows the building envelope components can be recognize as individual objects. The simplistic geometric outlines of all the components are recognized and ready for energy analysis.

Complex freeform structures are one of the most striking trends in contemporary architecture. This direction has been pioneered by architects such as F. Gehry, S. Calatrava, Zaha Hadid and others (Fig.1). One of the most effective concrete structural emblements used to execute freeform structures, are shell structures. The shells are most commonly flat plates and domes, but may also take the form of ellipsoids or cylindrical sections, or some combination thereof. Its efficiency is based on its curvature (single or double), which allows a multiplicity of alternative stress paths and gives the optimum form for transmission of many different load types. Formwork used to execute shell structures represents a major consideration of costs, and involves a significant proportion of the total cost.

More and more design and construction professionals in Architecture, Engineering, and Construction (AEC) areas have been and now are using Building Information Modeling (BIM). Unfortunately, there were very few efforts exploring the real-time communication and integration of BIM to the site and task conditions, and the interaction of BIM with the field crew. It is envisaged that Augmented Reality (AR) can fulfil this vision effectively through visualizing BIM right into the physical context of each construction activity or task. This paper develops a conceptual framework to investigate how BIM can be extended to the site via AR. Human factors are the core principle to investigate on, considering that AR, by nature, involves the human sensations with both real and virtual information sources. It is also found that AR should be ubiquitous and work together with accurate positioning technologies such as laser pointing.

Successful management of design changes is critical for the efficient delivery of construction projects. Building Information Models (BIM) and the use of parametric modeling provide significant benefits in coordinating changes across different views in a model. However, coordinating changes across several discipline-specific models is significantly more challenging to manage. This paper describes a case study that examines change management in the context of a multi-disciplinary collaborative BIM environment during the design and construction of a fast-track project. We documented the design changes, analyzed the change management processes and evaluated existing BIM tools in support of this process. Using two examples from the case study, we identify the characteristics of design changes required for tracking the history of changes and understanding the consequences of changes. We develop an ontology of changes based on the identified characteristics and patterns in the observed changes. The ontology characterizes design changes based on changed component attributes (the geometry, position, and specification), and based on dependencies between components (analytical and spatial). We further examine what needs to be updated in an information model corresponding to each type of change. The results of this study provide some possible directions for future developments in change management systems, particularly in reference to a BIM-based delivery process.

Construction operations have been modeled and simulated using Discrete-Event Simulation (DES) with effectiveness and fidelity that has continuously increased over the past four decades. Construction operations often include activities that are simultaneously continuous and stochastic in nature and these activities have typically been modeled by discretization and in some cases using combined discrete-continuous simulation, which presents severe limitations and difficulties in accurate modeling of the system under study. This paper presents a combined discrete and continuous approach that utilizes methods optimized for modeling and simulation of continuous construction activities within the three phase scanning algorithm of a discrete event simulator. The approach includes support for modeling dependent data set, mixed modeling of discrete and continuous activities, discrete and continuous resource flows and other algorithms to improve accuracy and efficiency of the modeling process and simulation results. As part of the study, these methods were implemented as an extension to STROBOSCOPE, a powerful DES tool optimized for construction simulation. A case study of road paving operation is presented to demonstrate improvements and advantages of the combined approach for modeling and simulation of discrete and continuous models for construction operations.

The advance rate of tunnel boring machines mostly depends on complex interactions between supporting logistics rather than TBMs' penetration rate. Transporting material inside the tunnel, handling trains and material at the tunnel entrance, and production of concrete segments are the three main supporting processes that can significantly affect project performance. This paper represents development and application of a dynamic simulation model using system dynamics. The model includes processes involved in concrete segment production plant and material transportation system. The developed model suggests the number of cast sets and the curing method in order to properly produce segments. Suggestions are based on everyday tunnel production, characteristics of each curing method and current condition of the limited storage area. Moreover, the model allocates appropriate number of trains to the project on the basis of every day excavated length, trains speed and duration of activities at each end of the tunnel. Based on the model results, the segment production plant will be managed accurately focusing on providing needs of the TBM and making the storage area full within a short time. Simultaneously, the allocation of additional trains to the material transportation system is done appropriately.

A web-based 3D game project was presented in this paper to demonstrate the process of using building information modeling (BIM) to create an interactive 3D on-line ‘Green' training environment. The system architecture, the implementation process and major components of this virtual training environment were discussed. Existing studies on BIM-based collaborations mainly focused on local-file-sharing approach using proprietary applications. Limited research focused on using BIM as an online gaming platform to create a web browser-based interactive 3D virtual environment for collaboration, learning and/or training. The gap was partially caused by the lack of understanding how to implement a BIM-based game in web browser environment. In this paper, the authors provided an implementation example using a hospital BIM model to create an interactive web-based 3D BIM game environment to allow users to visualize and interact with the BIM components using regular web browsers. The intention of this project is to create a proprietaryindependent training environment to conduct energy re-commissioning trainings for hospital facility management staff. This virtual BIM environment can potentially be customized for engineering student learning and project collaborations as well. The conclusion was that current BIM and game technology are mature enough to allow us to create serious web-based interactive learning/training virtual environment. The successful integration of BIM and web browsers paved the way for many learning and training applications, which need built-environment as context.

Uncertainty is an entrenched characteristic of most construction projects. Most research works in simulating construction operations have focused predominantly on modeling and has neglected to study the effect of subjective variables on simulation process. Data mining is used to extract hidden knowledge from a data set, which would not be readily obtained by traditional methods. There is a significant need for a new generation of techniques and tools with the ability to automatically assist humans in analyzing the mountains of available construction data searching for useful knowledge. The presented research develops, using Fuzzy approach, a data mining engine to utilize, analyze, extract and model the hidden patterns of the project data sets to predict the work task durations. The engine depends on finding the relation between quantitative and qualitative variables, which affect the construction processes, and work task durations. It consists of five steps: (1) select the factors that affect the construction process; (2) build Fuzzy sets; (3) generate Fuzzy rules and models; (4) build Fuzzy knowledge base; and (5) validate the effectiveness of the built knowledge base to predict the work task durations. The developed engine is validated and verified using case study with sound and satisfactory results, 92 % average validity percent. The developed research/engine benefits both researchers and practitioners because it provides robust knowledge base for construction processes and a tool to predict the related task durations for construction activities.

Availability and accuracy of building information is critical for a variety of tasks during the lifecycle of facilities. Currently Building information modelling (BIM) is mostly used for design and construction. When the as-designed BIM is not updated with the construction changes, it can contain inaccurate information. A way to collect the as-is conditions is to capture how a facility is changing over time. Vision-based data capture technologies, namely laser scanners and cameras, are being widely used. However, occluded components and the challenges associated with reverse engineering of complex construction objects can result in incomplete as-built data. This paper presents a case study, in which a laser scanner and a camera were used to capture the construction history and develop a more complete as-built BIM. A progressive approach is followed to mitigate challenges associated with cluttered construction data. Components/features occluded in any captured scans were reconsidered throughout a continuous planning and data capturing process. Other sources such as as-designed documents are supplemented to as-built data for extraction of information items required for the as-built BIM. The discussions include more ample description of the background research and the addressed problem, followed by detailed description of this study's approach. Lessons learned, findings and recommendations for future research are summarized.

Based on a case study of the city transformation of Kiruna we concluded that the information about the urban planning processes; (1) was scattered and hard to understand and (2) not communicated properly for the public to be able to participate. Here public participation geographical systems (PPGIS) and modeling of a project delivery timeline, also known as 4D, are possibilities to improve communication with stakeholders in urban planning and construction processes. As a result, we set up three requirements for the development of a 4D PPGIS communication platform. Firstly, time-space urban planning information must be available and understandable for the citizens to comprehend. Secondly, the communication platform must support two-way asynchronous communication for collecting public opinions and proposals. Finally, the user interface, operations and management of the platform must engage citizens to participate in the urban planning process. An experimental 4D PPGIS based on Google Earth and Facebook services was developed to visualize geo-referenced past, current and future urban activities and support public discussions regarding planning proposals. The prototype is currently being evaluated in the first iterative cycle of the information system development method.

Space on construction site is a limited resource. Building elements, construction activities, and material storage and access compete for limited spaces throughout the entire project life, leading to space conflicts that occur frequently on site. Space conflicts could substantially hinder the performance of interfering activities. Both academic and commercial computer applications are available to detect solid-solid conflicts (physical geometry crashes) among site objects, but space-solid overlaps and space-space overlaps are not well supported, especially for objects with complex shapes. In addition, very few researches incorporate the evolution of the workspace. A challenge exists in how to efficiently store, represent, and update the geometry data. This paper presents a study on buffering workspaces of arbitrary shapes and detecting the space-solid and space-space overlaps in a 4D context with an implementation on the platform of Geographic Information Systems (GIS). The buffering approach is based on a Uniformly-Distributed Points (UDP) method that examines the distance between each point and a solid geometry with an arbitrary shape. The proposed method eliminates the needs to scan all the workspace geometries for analysis, especially facilitates the case that the workspace geometry is evolving along time. A prototype was implemented in a commercial GIS software package. Preliminary experiment results have revealed that the newly created buffering prototype can generate workspaces in any geometric shapes and detect the space-solid and space-space conflicts in an efficient manner.

A methodology is introduced which can visualize non-invasively measured energy efficiency of existing buildings through easily accessible web-based geospatial programs such as Google Earth^TM and Bing Map^TM. The disconnect between existing high performance building information and the willingness of decision makers to understand such information is likely due to the complexity of building systems and the lack of adequate feedback loops between decision makers and outcomes associated with the different stages of the building lifecycle. In this study, a hybrid thermal laser scanner was used to measure 3D geometry of a building and thermal performance of the building envelop. Several technical challenges in transferring a scanned model into a geospatial application were discussed. A preliminary field test on a residential house was conducted with promising results. The visualized building's thermal performance through easily accessible web-based geospatial programs can make the processes of building energy audit and retrofit decision making easier.

Building Information Modeling (BIM) and lean are two distinct concepts used in the construction industry which are independently applied to the construction process and provide profound impacts. Evidence shows potential gain if both BIM and lean are integrated. This research proposes an integrated model that applies both BIM and lean on a modular construction manufacturing (MCM) process and gains the benefits of both concepts. A computer tool for drafting the modular construction process called MCMPro was expanded to generate the building components' schedule. The Value Stream Map (VSM) of the factory is generated based on the components' schedule through a proposed Integrated Process Improvement (IPI) method using a set of mix lean principles to reduce waste over a broad range of factory activities. A simulation model using Simphony.NET 3.5 is developed to run the generated VSM and produces the results. The proposed methodology is validated by a case study, which is a modular building located in Edmonton, AB, and illustrates the effectiveness of the proposed methodology.

Large scale construction projects often involve the lifting of heavy equipment. With increases in equipment size, lifting operations create new challenges in crane selection. In terms of safety, stability is one of the most important factors to consider when selecting cranes. Although practitioners often apply simulation tools to select appropriate cranes, the effect of wind on crane stability is not yet considered in the selection process. Considering that cranes are among the most expensive types of equipment, contractors need to plan the crane operations properly to improve safety and reduce cost and time. This paper presents a methodology to implement the safe operation of cranes by identifying possible crane instability caused by strong winds using Building Information Modeling (BIM), a tool which prepares smart designs to integrate and coordinate cross-disciplinary designs, the construction process, and facility management decisions. A methodology is proposed to integrate wind effects on crane operations which can be considered a major step in developing future BIM. Through a case study involving multiple heavy lifts in an industrial project, the benefits of the proposed methodology are identified.

With North American population increasingly aging, it is to expect that new strategies to improve the built environment in order to accommodate the new needs of the population proliferate everywhere, such as installing receptors in the houses, decreasing maintenance or increasing adaptability. Universal design (UD) is the design that is oriented to meet the requirements of the largest number of users, people of all sizes and abilities, including seniors, people with physical or sensorial disabilities, children, and pregnant women. This paper presents a methodology that integrates Building Information Modeling (BIM) with database management system for designing universal buildings and homes. The methodology describes the development and implementation of a model that incorporates comprehensive databases storing architectural components and systems in an attempt to simplify the process of creating universal designs based on the National Building Codes of Canada (NBCC). Designing the model in a user-friendly environment allows owners and engineers to design and animate sustainable buildings that are universal in 3D mode easily and efficiently at the conceptual stage. A case example is presented to illustrate the usefulness and capabilities of the developed model.

Today's project teams face many challenges in meeting a diverse set of objectives. Fortunately, integrated project delivery and the modeling tools that it incorporates offer major potential benefits in meeting these challenges. The purpose of the paper is to analyze integration of structural and construction engineering on projects and make recommendations to increase integration and enhance performance in meeting project objectives. The paper describes the context and project steps for integration and analyzes two project examples to highlight conclusions and recommendations regarding integrating structural and construction engineering to increase project performance.

Simulator For Construction (SimFC) is a construction-related simulation platform which allows for modeling of various construction processes in a controllable and repeatable manner. These processes can vary in complexity and size involving various resource requirements and time constraints. However, SimFC is also a versatile general purpose simulator which allows users to easily model almost all entity-relationship based systems using the elements provided in the visual environment. On the other hand, planning for airport human resources is often a challenging task especially when factors such as airplane delays, passenger check-ins, luggage inspections and passenger wait time policies are considered. This paper discusses a simulation model of passenger check-ins and security checkpoints at the Calgary International Airport using SimFC. A simple case study of US bound passengers from Calgary is presented. Based on passenger throughput levels and traffic intensity, airport-level human resource allocation recommendations for the number of check-in agents and passenger facing security personnel are made. The findings are of particular interest to researchers and industry professionals involved in airport service planning and management.

Today construction operations can be modeled and simulated using Discrete-Event Simulation (DES) with effectiveness and fidelity that has continuously increased over the past four decades. However, construction operations often include activities that are simultaneously continuous and stochastic. Continuous activities have typically been modeled by discretization and in some cases using combined discrete-continuous simulation. Discretization brings important statistical issues related to divisibility of fitted distributions and a significant possibility of the discretized activities not being Independent and Identically Distributed. Combined discrete-continuous simulations have treated the continuous portion dynamically (i.e., based on differential equations of rate change) but disrespecting the statistical properties of the underlying stochastic process. Most of these issues can be attributed to either limitations of the modeling tool or assumptions by the modeler. These assumptions and limitations can seriously affect the accuracy of the model, grossly impact the simulation results and can be detrimental to the acceptance of the model due to difficulties in verification and validation. This paper presents a case study of a road paving operation to investigate the major issues associated with modeling continuous stochastic construction activities, highlights possible sources of error and demonstrates their effect on the simulation results.

This paper presents a new carbon footprint monitoring tool that enables contractors and managers to reliably and effectively benchmark, monitor, and visualize expected and released embodied carbon footprint of a construction project. The proposed method is based on generating Dn_{AR - n dimensional augmented reality - models in which the expected and released embodied carbon footprint of a project are jointly represented in a common 3D environment. To accurately estimate the expected carbon footprint associated with different alternatives for material procurement and delivery to the jobsite, first the material information is queried from the underlying building information model. Next, using an embodied carbon footprint inventory associated with different materials and the distance of the suppliers to the jobsite, the expected carbon footprint is calculated for each construction schedule activity. In the meantime, the information from the contractor submittals is used to measure the released carbon footprint for the same activity. Finally, the expected and released carbon footprint associated with both material procurement and their delivery is compared in a new form similar to Earned Value Analysis and their deviations are visualized in the Dn}AR environment. The resulting visualization provides practitioners with an opportunity during coordination and submittal processes to not only insure timely delivery of materials, but also minimize the cradle-to-site carbon footprint of their projects. We present preliminary results from initial experiments of our proposed embodied carbon footprint monitoring system on a case study related to construction of a concrete substructure. The perceived benefits and applicability of the proposed method is further discussed in detail.

School buildings are one of the most important educational and learning environments and the appropriate design of these spaces has a significant impact in enhancing both students and teachers performance, comfort and satisfaction. As a result, the preliminary design evaluation and optimization of school buildings should be given a significant consideration. The key factor in design optimization of a school building, is defining the users' expectations, which is qualitative and subjective in nature. To capture these qualitative and imprecise aspects of the problem, and optimize school building design parameters, a multi-criteria fuzzy expert system is employed and the design evaluation and optimization model is developed. Different school building design parameters such as; building orientation and layout, envelope features, indoor air quality as well as day-lighting systems are investigated as part of the design evaluation and optimization process. The fuzzy expert system is used to analyze the optimal values of a list of parameters associated with the building design process to enhance the learning environment for school buildings. This method employs both quantitative and qualitative design performance parameters, and allows for different design alternatives to achieve the objective of the project.

Space planning of complex and congested construction sites affects construction safety and field performance. The traditional method of relying on visual inspection and 2 dimensional (2D) drawings for layout planning is limited by the fact that construction sites are usually highly complex and dynamic. Existing site conditions must be frequently captured to represent its latest status for space planning. Recent development of 3 dimensional (3D) reality-capturing technologies, such as laser scanning and photo-based modeling, allows an accurate measurement of a job site and its representation in a 3D format. This research proposes a photo-modeling approach for capturing as-built conditions for space planning purposes. This technique automates the reality-capturing process in which a series of 2D photos taken from different perspectives are used to derive an as-built 3D model of a construction site. The feasibility and effectiveness of the proposed approach is demonstrated in an industrial case study.

Construction resource planning and control is traditionally done using static data and information available from similar projects. However, the uniqueness of and uncertainties involved in each construction project may require that field data from equipment is dynamically collected, analyzed, and integrated into the decisionmaking process in order to achieve the best possible operational plan. The collected data can be used to predict the performance of a construction system based on the latest status of the project, as well as to monitor if all pieces of equipment are operating according to the plan and if any corrective action is needed. This paper presents the results of a remote tracking technique developed to capture field data from construction equipment in real time for short term monitoring and control of construction operations. The developed technique uses a .NET environment thus providing a convenient means for data collection, sorting, filtering, and interpretation. The collected data is time-stamped and thus, can be used to create a real time 3D animation stream of the ongoing operation. This facilitates the communication of project details and can be ultimately used as a verification and validation tool for the underlying simulation model.

Augmented Reality (AR) is commonly used in the construction industry to visualize proposed structures and/or operations in their real world environment as it greatly enhances the realism of the viewing experience without having to construct 3D models of complex real world scenes. In order to achieve convincing scenes in AR applications, the virtual objects should be correctly occluded by the real objects present in the scene, which is a non trivial problem that involves specialized equipment to capture depth information about the real scene. This paper presents a novel methodology that allows for the stereoscopic rendering of AR scenes with the correct occlusion of the virtual objects. Two pictures of the real scene that are captured simultaneously from viewpoints with a horizontal baseline separation of 1m are used to obtain both the stereoscopic images as well as the depth information of the occluding objects in the real scene. Potential applications of this methodology include its use in the creating and rendering engaging representations of the AR scene being visualized, by affording the user the perception of depth in the scene and as novel means to visualize 3D CAD and BIM models in their proposed/ existing settings in the real world.

Commercial buildings are responsible for 19 percent of the total energy consumption in the United States (US) and are projected to expand their share of energy use at increasing rates. Saving energy in the commercial building sector has therefore become the focus of many governmental initiatives. The first step towards more energy efficient buildings is improving design. Optimizing the sizing of mechanical and electrical systems is particularly important as it highly affects the buildings' life-cycle energy use. Consequently, designers and engineers are using energy modeling and simulation to compare different systems and predict building performance. Large discrepancies are however being observed between predicted and actual building performances. In order to improve these predictions, the sensitivity of energy models to different input parameters needs to be evaluated. Although proven to significantly affect energy use, occupancy related parameters have rarely been evaluated. This paper presents a sensitivity analysis study performed on the occupancy parameters of the most typical commercial building type encountered in the United States (US). Results indicate that occupancy chosen building temperature set points have the highest impact on energy use, while the influence of building schedule and after-hours equipment/lighting use is also significant, particularly in hot weather climates.

A special purpose simulation template (SPST) provides a specially built and easily understandable set of modeling elements targeted system managers who are not necessarily familiar with the simulation modeling concepts. Nevertheless, most construction managers fall into this category of the managers. In this research we have developed a SPST which facilitates development of the simulation models for the structural steel fabrication shops (SSFSs). These simulation models can help SSFS managers to observe the effects of any alternative modifications to the shop layout or equipment prior to their actual implementation. These models ultimately improve the shop productivity by suggesting the most appropriate alternative modifications. At this stage of the research the development of the SPST has been finished and its capacities have been tested on a SSFS. As the future steps of the research the developed SPST is going to be validated and applied to the real SSFSs cases and introduced as a useful tool to the SSFS managers.

In recent decades, several sectors of the economy (aviation, shipping, power generation, healthcare, etc.) have emphasized teamwork as a key strategy for systematic error management and accident prevention. This study focuses on the role of team processes in the safety of construction work groups. The paper first reviews the key teamwork constructs (cognitive, affective and behavioral attributes of teams) and develops a framework of teamwork attributes that are important for safety. This framework is based on an extensive review of the teamwork literature from several disciplines and sectors. Then, the framework is used to identifies the teamwork challenges in the context of construction operations. Finally the paper provides directions towards systematic improvement of the teamwork processes in construction crews.

Capital projects are funded with the intention of meeting a business need. For the delivery of the facility to be successful, the interface between the owner's business personnel and its project personnel must be effective. This paper outlines a quantitative approach for the measurement of this management interface; an approach which has not been accomplished to date. Although previous studies examined various technical interfaces among project personnel, the interface between business and project personnel is in fact, more important to ensuring the realization of the project's stated benefits. Therefore, this research conducted a thorough literature review on studies related to organizational interfaces and their management in the construction industry. It also examined quantitative measures of organizational involvement and the interface between business and project units. This paper concludes with some recommended quantitative assessment tools able to measure the involvement and interaction between business and project personnel assigned to develop a specific capital project.

Work sampling has been used to indirectly measure crew productivity. Although favoured for being less costly, easy to adopt, and able to provide quick information, previous work sampling studies have not gone beyond identifying the direct, support, and delay proportions of activities to provide a reasonable estimation of productivity. Research into identifying a relationship between work sampling results and productivity has been limited, and an approach to identify the most productive proportion of direct and support activities for different trades has not been developed. This paper proposes a research framework for crew-based work sampling, supplemented by foreman delay surveys and craftsman questionnaires, to establish a relationship between work sampling and productivity, and to identify the effective proportions of direct and support activities for different trades. The paper describes the development of this framework and illustrates the analysis involved by using case study data. Ultimately, this framework will be used to develop a crew-level productivity analysis model, based on subjective and objective factor modeling, supplemented by work study methods, including work sampling.

Extensive research has been conducted to improve construction safety. This has partly contributed to significant safety performance improvement of the U.S. construction industry over the past 20 years. However, the construction industry still accounts for the most fatalities of all U.S. industries. Therefore, it is still a long way to go for the U.S. construction industry to achieve the goal of zero accidents. Since 1990, the Construction Industry Institute (CII) has conducted an annual safety survey concerning its members' overall safety performance. As a whole, CII members experienced substantially better safety performance when compared to the overall U.S. construction industry over the past two decades. This paper presents the results of a recent CII Annual Safety Survey completed by 53 leading construction organization in 2009. Based on these results, a follow-up survey was administered to those companies to investigate the common attributes among those companies in order for other companies to emulate those attributes that likely lead to improved safety performance. This paper facilitates the industry's effort to move toward the zero accident goal by providing new comprehensive benchmarks of safety performance for owners and contractors.

Recent studies have shown that 80% of the baby boomer generation who have critical "know-how" and "how-to" knowledge and skills will be retiring within the next 10 years. Also the American Society of Civil Engineers (ASCE) predicts a significant shortfall of engineers in the next decades. In many companies, the retirement of the senior employees basically translates into the retirement of their years of experience and knowledge as most companies do not have well planned strategies and methods to retain the knowledge and skills of their retiring employees. Decades of downsizing and outsourcing management practices also have exacerbated this problem. There have been rich research efforts outside the construction industry on the importance of knowledge management (KM) which emphasizes the collection and managed sharing of knowledge within the organization. Furthermore, learning organization concepts as an evolved framework from KM have been established as dynamic and effective environments for proactively capturing, sharing, disseminating, and retaining knowledge and skills. This study investigates the effectiveness of the methods used to retain cost estimators' knowledge and skills and evaluates the significant effect of the organizational learning environment in promoting the continuity of learning, and knowledge and skills development. The Structural Equation Modeling method (SEM) was employed to investigate and assess the causal relation between the learning environment provided and the retention methods used. The findings of this study will significantly improve engineering and construction companies' practices in retaining cost estimators' knowledge and skills, and help companies adapt a healthy learning environment that can facilitate learning and sustain knowledge transfer.

An organization's culture has an indirect but significant effect on the performance of its workers. The development of a positive organization culture in construction projects is especially important, because most operations in construction projects rely heavily on a workforce. Further, new members in construction projects constitute a new project organization, and so can develop either a positive or negative culture. Group norms in organizations are a clear manifestation of the culture. Within this background, the objective of this paper is to demonstrate the effect of group norms on the absence behavior within projects and to explore absenteeism control policies using agent-based simulation research methodology. To fulfill this objective, we investigate the dynamic mechanisms of the formation and exertion of group norms among workers, model them as a computer simulation model, and identify control factors underlying these mechanisms using the simulation results. We discuss: when and how absence norms take effect, the importance of education in a worker's unbiased understanding of others' absence behavior, and the effect that a worker's attachment to a project has on his/her absence behavior.

The inter-firm collaboration networks created by international construction contractors have greatly influenced not only project success, but also potential business opportunities. However, despite the significance of collaboration, current research about organizational networks focuses on project teams and the limited collaboration among participants in a single project. This study consists of a preliminary investigation of 1) how the structure and properties of inter-firm collaborations change over time and 2) which network properties have the greatest effects on the business performance of member firms. To this end, this study analyzes cases of collaboration between Korean construction firms involved in international projects over the last decade. Periodic networks were developed and a longitudinal analysis was conducted to find empirical evidence. The results show that as the size of inter-firm networks increases, the networks become denser and center around the most densed large group. The results also indicate that the centrality of individual firms has a positive correlation with future contract revenues, especially considering the two-year lag.

Increasingly, most organizations in the construction sector use teams to meet today's global competition and customer expectations, but they need better ways of evaluating the effectiveness of the teams. To ensure that construction teams are successful and effective, construction companies must promote, measure, and evaluate their teams' effectiveness. It is believed that creating a highly effective project team will produce high-end project outcomes that exceed standards, and, therefore, enhance overall productivity. This paper discusses a method for designing a survey to measure the effectiveness of construction project teams. First the paper describes the steps in designing a survey, and then focuses on the statistical processes used to establish reliability and validity. The survey is pretested and analyzed using explanatory factor analysis to reduce the number of variables and to detect the structure of the questionnaire from the relationship between variables. The paper reports lessons learned during the development of a survey, provides the survey, and offers suggestions for future research

Public Private Partnerships have gained popularity as a mode of delivery for infrastructure projects in India. The institutional contexts surrounding these projects constrain or enable the smooth execution of these projects. In this article, we explore the key capabilities that need to be present in the institutional environments surrounding the projects - clear rationale, legitimacy, political willingness, advocacy, predictability and commitment in decision making and capacity to develop and monitor projects - which can be developed through a variety of institutional forms and actions. We then assess the institutional environment in the state of Tamil Nadu in India, in terms of these key capabilities and examine 6 PPP project case studies in the light of this capabilities framework. We focus on the impacts of the various capabilities on the PPP infrastructure projects. Based on this empirical evidence, we conclude that the gaps in institutional environment surrounding a PPP project can cause significant governance issues in projects and actions of the project proponent's aim at filling out these gaps in the environment to tackle these issues. The paper contributes to our understanding of the impact of institutional environments on the governance of PPP infrastructure projects.

This paper suggests a new theoretical lens to understand and manage construction design processes that draws on Heidegger's theory of deliberate action (Heidegger 1963). The lens interprets the day to day activities of designers as being immersed in practice without deliberate attention to everyday actions. Being immersed, designers do not reiterate the initial problem context and will only design for initially de_ned criteria. Only if the day to day ow of immersed practice is interrupted or is breaking down designers will involve in what Heidegger calls "involved thematic deliberation" or "theoretical detached deliberation" (Sandberg and Tsoukas 2011) that allows them to reiterate the initial problem context. This early position paper, introduces this new theoretical lens and shows its value by analyzing a number of design episodes that I observed during my ongoing ethnographic research work with designers. The examples show that the new lens allows for a good understanding of the increasing problems of designers to identify the wide range of societal and engineering issues during post-modern construction design e_orts upfront. I posit that this better understanding, in turn, will support the better management of the changing problem contexts that occur on almost all post-modern construction design projects.

Engineering and construction organizations have become increasingly interdisciplinary and global to meet the demands of complex projects around the world. These organizations can gain a competitive advantage by sharing knowledge collectively across disciplines and geographic regions. Knowledge sharing connections (KSC) that span geographic and disciplinary boundaries can also increase performance at the individual and project level. As a result, organizations are particularly keen to create these boundary-spanning KSC within their global interdisciplinary networks. Unfortunately, these KSC are difficult to create as they span "long jumps" of physical distance and/or "high jumps" of functional silos and disciplinary knowledge. In addition, little is known about the relative importance of discipline and geographic location on the creation and maintenance of KSC in intraorganizational networks. To address this gap, this research employs social network analysis (SNA) to analyze the frequency of KSC that span disciplinary and geographic boundaries within globally distributed, interdisciplinary knowledge networks in an engineering organization. To further understand the origins and reasons for these connections, this research also examines the reliance that individuals within the network have on these connections and the directional flow of knowledge for each connection. Results indicate a higher frequency of connections that span disciplinary versus geographic boundaries, higher reliance on KSC spanning disciplinary boundaries than regional boundaries, and approximately equal relative frequencies of KSC that have bi-lateral sharing of knowledge These results can be used to prioritize knowledge mobilization strategies for multi-national engineering and construction organizations.

The Architectural/Engineering/Construction (AEC) industry comprises a large portion of the global economy, contributing significantly to gross domestic product (GDP) and employment. Entangled with crucial upstream and downstream industries, the AEC also plays an important role in the global supply chain; and monitoring the trajectory of the industry is therefore important for the individuals who are directly or indirectly involved in the industry. Nevertheless, analysts are deprived of tools specifically devised to evaluate the health of what we will now refer to generally as the construction industry. The available indices are essentially finance-driven and generic, disregarding the specific characteristics of the construction industry. Construction is known as a high risk, capital and asset intensive industry, involving large-scale projects with longer payback periods. This paper reports on the preliminary results of ongoing research at Purdue University, which would lead to the development of specific construction industry health indices. This research investigates the existing indices applied within the industry to identify gaps in the current literature and, most importantly, proposes a multi-dimensional definition of health for the industry. The interim outcome of the research is a methodological prototype that can be applied by decision-makers to develop indices that indicate current health of the industry. The final developed prototype could be applied to enhance protocols for strategic planning.

Construction activities are repetitive from floor to floor in multistory building construction. Labor productivity may neither reach 100 percent of the normal level at the very first floors nor the very top floors. Nevertheless labor productivity may follow a certain pattern as construction activities progress. This research aims at exploring the relationship between floor number and labor productivity in multistory structural activities, namely formwork installation and rebar fabrication/installation. The case study methodology and learning curve theory are adopted for this research. Records from the structural works of an apartment building were analyzed to calculate floor number-based labor productivities for the two investigated activities. The unit rate of the formwork activity reduced more than 50 percent in the first five floors. If the first cycle (floor 2) is omitted, the straight-line learning curve model shows a learning rate of 83.5%. Productivity of the formwork activity tended to level off in the remaining thirteen floors. The unit rate of the rebar activity was prone to reduce in the first fifteen floors. If the first two cycles are omitted, the straight-line learning curve model indicates a learning rate of 83.6%. If only the first cycle is omitted, the learning rate of the rebar activity is 87.9%. Productivity of the rebar activity tended to decrease in the last three top floors though data points were not adequate to confirm such pattern.

Construction industry is generally regarded as project based industry. Construction Project Management places large emphasize on planning and execution of the projects due to this project based nature of industry. Construction firms only consider project performance, the parameter to measure success, neglecting importance of strategic planning and management for higher profitability and quality business operations. Rapidly changing social and technological issues are creating such a professional environment that will enhance the need of strategically defining organization's goals in the construction industry in coming decades. To meet such a challenge, requires identification of current industry level practices. This study tries to identify the current nature of strategic management concepts and practices by the construction firms in Pakistan. Results have shown that strategy evaluation, research and development and use of management information system as a decision tools lacks in the construction industry. It is recommended that construction industry should join hands with the academia to undertake certain research & development projects that can benefit both of the parties.

This paper discusses how the role of financial loss reduction as related to site injuries through financial measures can promote sustainable management of infrastructure projects. The available research database include various studies concerned with monitoring, evaluating, expanding, repairing, replacing, financing, or otherwise sustaining the civil infrastructure. Only few studies though address the ongoing and evolving financial problems associated with the workers responsible for developing our civil infrastructure development. Civil infrastructure projects employ around 8% of the nation's workers, yet accounts for approximately 22% of the fatalities suffered in private industry. The dynamic combination of tools and equipment, heavy machinery, working at heights, and multiple workers at busy construction sites yields a potentially very dangerous workplace. Millions of construction workers in building, heavy, and special trade construction are at risk for fatal and nonfatal injuries. Workers are also at risk of injury or illness due to contact with objects, falls to a lower or same level, overexertion, and excessive noise. This study develops the basis of an evolving long term financial framework to quantify how loss reduction, as measured by the firm's efforts to improve employee satisfaction with the treatment of their claims, affects the perceived loss and cost of the claim. When completed, this research will increase the empirical knowledge about how human resource policy and practice affect workplace risks through loss reduction efforts.

Infrastructure projects are complex undertakings that capture public attention because of their magnitude and effect on society, the economy and the environment. Public opinion presents a source of great uncertainty in infrastructure development projects. For instance, a project might experience disruptions if there is public opposition due to project location or environmental impacts. In this study, a survey was deployed to quantify how project characteristics (reactor size, type of technology, experience of utility company, number of reactor units, etc.) could gear public opinion related to new nuclear power plant projects. A logit model was developed for each project characteristic considering variables such as: (1) state-related characteristics (region in Nuclear Regulatory Commission, number of nuclear power plants operating in the state, etc.), (2) perceived risk of nuclear power pertaining to safety and to environmental aspects, and (3) the respondents' attributes (age, level of education, electricity consumption per month, etc.). The probability of individuals opposing a project with a specific set of characteristics was calculated using these models. The project characteristics that lead to higher probabilities of opposition were found to be (1) larger reactor size, (2) lack of experience of the utility company with nuclear power, and (3) presence of financial support from the government. The results of this research provide decision-makers with information that could be used to define the project characteristics during the planning phase in a way so as to mitigate public opposition.

The optimal solutions for the resource allocation problem are of great significant to project planners for distributing their available resources into the activities most effectively. Many studies have been undertaken to solve the resource-constrained project scheduling problems using genetic algorithms, which have been proven as an effective and efficient optimization tool to solve difficult and complex problems. One of the trends in the genetic algorithm research study is to develop a hybrid meta-heuristic method using artificial intelligence and biologically-inspired techniques. In an effort to address this issue, the author developed a new hybrid genetic algorithm to solve the construction resource-constrained project scheduling problems. This paper evaluates the parameter effects of the hybrid genetic algorithm for optimization because optimal settings of the genetic algorithm parameters such as population size, crossover probability, and mutation probability, are critical conditions in producing the best value for the outcomes.

Some study show that the performance of DBB projects depend upon the quality of the design. If errors are minimized during the design phase, then, construction costs are reduced and schedule growth are minimized. Therefore it is necessary that owners focus more on the project's design phase in order to improve the construction project performance. Based on prior research, this study hypothesizes that there are relationships between design costs and construction project performance of DBB public projects. Data was collected and analyzed regarding design cost, construction award cost, final construction cost, and construction duration of a set of DBB public projects. The analysis showed that the design cost was significantly correlated with construction cost growth and schedule growth of the public projects under evaluation. In addition, the design cost was found to have a significant correlation with the final construction cost. Using, a regression model developed to predict the final construction cost of a road project, and also using the design cost as an input variable, the R-square value of this model was found to be 58.7%. This result indicates that when design costs are higher, project construction performance is better.

Scarcity of construction site space imposes serious challenges for contractors in planning material supply and site logistics. Existing models of material logistics and site layout planning face critical performance limitations in congested construction sites, due to their inability of modeling and utilizing interior building spaces for long-term material storage. This paper presents the development of a new Congested Construction Logistics Planning (C2LP) system that facilitates the optimal utilization of interior building spaces by considering shifting some of the non-critical activities in order to generate sufficient interior space for material storage areas. Accordingly, the model is designed to optimize two main conflicting objectives; minimizing site logistics costs and minimizing project criticality. Site logistics cost include material ordering, stock-out, carrying, and layout costs. These two objectives are optimized considering four main categories of decision variables: material supply, interior storage plan, exterior layout, and shifting of non-critical activities. The model is designed to incorporate a group of critical constraints, such as exterior layout and activities-materials spatiotemporal constraints. The performance and capabilities of the proposed model are evaluated using an application example of the construction of a multi-storey building in a congested site.

This paper presents a stochastic approach for optimization of significant parameters of project control such as duration and budget in construction projects with Genetic Algorithm (GA). Increasing of uncertainty in project executions encourages the project planners to model construction projects by stochastic optimization methods. In this study, GA is considered as a controlled Markovian process in selection, mutation, and crossover stages which are incorporated into an explicitly given transition matrix. The non-stationary Markovian chain representation of GA is applied to construction project as an example to optimize total project cost and duration with stochastic critical path method. We also consider the asymptotic of the steady state distributions as population size increases. The proposed approach improves the project planner estimation during the project feasibility study stage to avoid project delays and over budget.

Private sector investments in public infrastructure projects have witnessed a tremendous increase over the past decade. The lack of government resources coupled with the need for expanding new and renewing exiting infrastructure has created a viable market for private infrastructure investments. Proper allocation of risks in public private partnership (PPP) projects has been identified as one of the critical success factors of these projects. Revenue risk is a common risk item in most PPP projects due to the long contract duration of these projects. Government Minimum Revenue Guarantees (MRG) is a common risk mitigation strategy whereby the government guarantees that project revenues will not fall below a specified limit during the contract. This guarantee is only redeemable at distinct points in time, so takes the form of either a Bermudan option, or a Simple multiple-exercise real option, depending on the number of exercise rights afforded. In this paper the valuation of this real option is done through the application of the Multi-Least squares Monte, and Multi-Exercise Boundary methods. These methods combine the use of Monte Carlo simulation, and dynamic programming. The quantitative approach offers more flexibility than other prevailing methods, and facilitates the contractual and financial negotiations in such projects. Two case studies of waste water treatment plants are examined. The first considers the construction of the treatment plant in one stage while the second considers the contractual requirement of phasing the construction of the plant in two stages.

Design of glass curtain wall (CW) systems has long been under the influence of structural, thermal and daylighting performance requirements as well as cost and aesthetic concerns. However, environmental life-cycle impacts of the systems are usually ignored when selecting the suitable materials for mullions and glazing units. This paper intends to examine the effect of mullion material change on the environmental impacts of a typical CW system over its life-cycle. The mullion materials studied in this paper include extruded aluminum, carbon steel and glulam timber. The environmental impact categories of interest include global warming, acidification, eutrophication and human toxicity. In addition, the paper applies a process-based Attritional Life Cycle Assessment (LCA) technique to achieve its objectives. According to the results of this study, an extruded aluminum CW system contributes most to the environmental impact categories of interest in this research while a glulam timber CW makes the least contribution. Contribution of steel CW systems falls in-between.

The need to evaluate wastewater treatment systems for their application to sustainable neighborhood design has become increasingly important in the last few years. New advances in wastewater treatment, called community-scale technology, indicate it may be possible for small communities to manage their own wastewater. This case study used the "triple bottom line" tenants of economic, environmental, and social factors to evaluate the use of community-scale wastewater treatment in a rural town in Northern Colorado. The study found that many features of the wastewater treatment system, including lower capital costs, less resource use, energy-efficient systems, the potential for water reuse, a smaller plant footprint, odor-control systems, and high-quality effluent are sustainable within the neighborhood, but there are also challenges. From a municipal perspective, a wastewater treatment system that requires more development to pay for the infrastructure gives a community the potential to create unwanted sprawl. However, a small-scale system may allow a community to be more self-sustaining in municipalities that employ good land use practices and strive for positive relationships with other governing bodies. Innovative approaches to municipal services, such as small-scale wastewater treatment systems, can offer new alternatives in this field. Cooperation with nearby governing bodies and rural service providers, as applicable, is essential to the implementation of such innovative technology for sustainable rural development.

The significant amount of waste generated from construction demolition has become a chronic problem in several developing countries. Using data obtained from demolition contractors and various other sources, this paper proposes a framework for proper handling of construction demolition waste (CDW) in countries suffering from lack of national CDW management procedures and facilities. This framework, which serves as a decision support tool, is then applied to the case of Beirut, and a sensitivity analysis is carried out to examine the economic feasibility of developing a recycling facility. The analysis shows that the feasibility of introducing a new recycling facility is highly dependent of the interrelationship between the landfill tipping fee and the recycling gate fee coupled with the marketability of the by- product as well as regulatory enforcement to control illegal dumping and properly manage engineered landfills.

Transformative technologies such as Photovoltaic (PV) system have promising features for substantial reductions in carbon emissions and environmental footprints of the building sector. Nevertheless, investment in PV systems requires substantial implementation costs followed by a long period of recovering the invested capital through savings in electricity bills. An appropriate investment valuation method is needed to conduct tradeoff analysis between electricity saving benefits and implementation costs, and find the proper investment values of PV systems. Currently, the valuation of investments in PV systems are made based on the conventional methods, such as payback period, return on investment (ROI) and net present value (NPV) (Muldavin 2010; Prindle and de Fontaine 2009). However, these methods have considerable limitations for the proper valuation of the investments in PV systems for buildings. The existing methods do not address two major issues that impact the value of such investments: uncertainty and timing. We present new approach towards the valuation of investments in PV system for buildings that challenges the theoretical foundation of current investment valuation methods. We utilize the Real Options Theory to overcome the limitations of existing investment valuation methods. We propose a novel investment valuation model that accounts for changes in the implementation costs of PV systems as well as uncertainty about their respective electricity saving benefits. This investment valuation model can be used to find the optimal time for implementing PV systems for buildings, as well as the financial value of properly-timed investments in PV systems.

High performance buildings such as hospitals and laboratories require intensive ventilation in order to meet operational demands. One way of reducing cooling in these types of buildings is to incorporate hybrid ventilation in public spaces. Depending on a variety of criteria such as internal and external conditions (e.g., temperature, humidity and required loads) these public spaces can be more appropriately cooled through hybrid ventilation than mechanical cooling. This research establishes an experimental approach to collect and analyze data from an occupied high performance building utilizing hybrid ventilation (HV) in public spaces. To optimize the use of HV, the research focuses on tracking three performance criteria: energy savings, occupant comfort and indoor-air quality. This experimental approach is illustrated through a case study example that recorded cooling load savings of 22Wh/m₂ per day and resulted in the selection of an ideal hybrid ventilation strategy for the particular space studied.

This paper quantifies carbon emissions due to on-site equipment use in the post-tensioned slab foundation construction process of production homes in Phoenix Arizona. The construction activities performed during post-tensioned slab foundation construction, trades/sub-trades/vendors and the list of construction equipment used for every activity are identified. Data collection involved field visits to several subdivisions, interviews with trades, quantification of use time and the fuel use rate for each equipment as well as the fuel type used for every construction activity. Emissions from fuel consumption were quantified using the guidelines provided by the U.S. Environmental Protection Agency. Analysis of emissions indicates that the concreting trade, the plumbing trade and the grading sub-trade are the three most significant trade components. Activities ‘set floor', ‘plumbing', ‘pour floor' and ‘backfill and grading' are the four most significant construction activities. Emissions of on-site equipment use are in the range of 4 to 15% of emissions due to transportation. This study is useful for home builders, trade contractors and vendors involved in production home building construction to measure emissions of on-site construction processes, identify significant construction activities and trade components and plan for improvement.

Construction waste frequently comprises a substantial percentage of the total waste received at the landfills in many cities around the world. To protect the environment and achieve sustainable development, efficient construction waste management has drawn more and more attention of various stakeholders especially government authorities, who are responsible of managing construction waste and have established a series of construction waste management policies, for example, landfill charging scheme and compulsory construction waste management plan. These policy instruments could be examined from three perspectives: construction waste management hierarchy, complementary policies, and parties impacted by policy instruments. An effective construction waste management policy framework should reflect the waste management hierarchy, involve as many parties in the construction waste management chain as possible, and establish instruments according to their dependency relationships.

Contractors are looking for ways to incorporate sustainable business practices into their daily operations that reduce cost. Diverting waste from the landfill is one way that contractors can reduce the environmental impact of construction. Construction is the largest contributor to landfill waste and concrete accounts for a significant portion of that waste. In turn, concrete waste can easily be recycled and reused as aggregate base course under roadway pavements and building slabs. Using recycled concrete in this manner reduces the environmental impact of construction by diverting waste and limiting the amount of virgin aggregate required for construction. Since aggregate is a finite resource, recycling and using recycled concrete limits the quantity of natural resources needed to support construction activity. This research identified barriers and drivers associated with recycling concrete and using the recycled material in new construction in the Phoenix metropolitan area. Data was collected through interviews with general contractors, demolition contractors, concrete recyclers, and engineers, as well as observation of jobsite activities. The results of this research revealed that the infrastructure for recycling and reusing concrete material is in place but there is a need to establish that recycled concrete is an acceptable material for use as base material in the Phoenix area, and there is a need for education and awareness among the stakeholders. Factors impacting the decision to recycle versus sending concrete debris to a landfill were not cost and proximity as expected but were the result of existing relationships contractors have with disposal locations. The factors impacting whether or not to utilize recycled material were lack of enabling standard specifications, perception of risk, and the regulatory environment of the municipality where the construction takes place.

Carbon footprint is commonly defined as the total amount of greenhouse gases produced directly or indirectly as a result of an activity. The term carbon footprint has become the standard for measuring the environmental impact of activities in several sectors (e.g., transportation, energy, construction). While there have been several studies documenting calculators that estimate the carbon footprint of individual activities (e.g., driving a car, riding an airplane), the literature describing the process of carbon footprint calculations for construction activities remains limited. The few existing tools that calculate the carbon footprint of construction buildings do not take into account some of the major variables in the design and construction process (e.g., properties of selected materials, location of suppliers). In an effort to improve the accuracy of carbon footprint calculations, this paper presents a tool that estimates the total carbon footprint of construction buildings while taking into consideration project characteristics (e.g., size, location, material choices). The calculator relies on data collected from construction material suppliers and covers the various phases of a construction project. Through a case study, the research team illustrates the use of the tool to identify the activities with high carbon emissions.

There is an increasing awareness towards the construction of sustainable green buildings. Green rating systems worldwide, such as LEED, are providing standards to aid in the construction of green building. During the pre-design phase of building projects, the designer evaluates various LEED credits in order to achieve maximum levels of certification considering project characteristics and owner requirements. This study proposes a simulation framework representing the LEED pre-design evaluation process to provide a decision support tool for the designer. The simulation control module is designed to regulate the overall process of green building predesign, which mimics linear evaluation of LEED credits in eco-charrette meetings. This framework will give the designer the power to investigate various what-if scenarios of different input combinations and the impact of his/her decisions on the building sustainability certification level.

Current practices of financial institutions in the US lack capability to differentiate—and accordingly underwrite—commercial energy efficiency investments from ‘normal' real estate investments. This deficiency in underwriting on projects and features of their building systems appears to lead to increasing perceived risks of commercial lenders. Consequently, loans that arguably should be funded on their own merits are not funded or delayed, or suffer higher cost of borrowing. In order to improve current commercial underwriting practices, the objective of this study is to develop a protocol to accommodate financial decisions in favor of energy efficiency. Through a series of interviews with industry practitioners, this paper examines the process of commercial loan underwriting in light of suggesting changes using Target Value Design (TVD) that, in the end, will lead to establishing a TVD protocol for underwriters and their customers to use. This study argues that the TVD protocol can align work processes of various stakeholders better than is done in current practice. For validation, feedback from small, medium, and large banks was obtained. Future case studies will further test the applicability of the protocol. This is part 1 of a 2-part paper.

Commercial loan underwriting for energy retrofits involves analyzing benefits and risks of energy efficiency (EE) improvement investments. We learned from interviews that current practices in commercial underwriting do not promote detailed collaboration between lenders and borrowers, and consequently erect financial barriers to making such investments. A Target Value Design (TVD) protocol to alleviate such difficulties was developed and is presented in Part 1 of this two-paper sequence. To support application of the TVD protocol, in this paper (Part 2) we focus on Step 4 "borrower-lender coordination," which is a key part of the protocol. In Step 4, the borrower and lender are encouraged to coordinate early on to collaboratively determine the loan size and loan terms and consider types of uncertainty in a specific EE investment. The objectives of this paper are to show how one can use Monte Carlo simulation in Step 4 to (1) categorize and quantify specific uncertainties in EE investments, (2) determine the target building performance, and (3) set the allowable cost based on the said target. While applying the results of interdisciplinary research funded by the US Department of Energy, this paper uses hypothetical data for the simulation. Future research using a case study is planned to further test the applicability of Step 4 and the TVD protocol in general.

Deconstruction significantly increases sustainability of the construction industry by shifting the traditional linear material usage model to a cyclical model in which building components are designed to be demountable, reusable and recyclable. A successful deconstruction strategy requires an elaborate planning at the design stage as well as clear strategies during demolition stage, describing the way each section of a building should be treated. However, a typical building comprises thousands of components with different unique properties. This leads to a huge amount of information that needs to be preserved and processed to achieve a successful deconstruction strategy. The development of various building information modeling (BIM) software as well as the international data exchange schemes such as IFC have recently facilitated the storage and processing of such information. The present study looks into the possible applications of BIM in recycling and re-use of construction materials and building components. A framework is developed for choosing the best deconstruction strategy by analyzing the information stored in BIM database. The results of a case study are presented to validate the procedures developed.

Green-roofs are becoming a popular breathing roofing alternative to traditional roofing systems. Green-roofs were mentioned as an ecological-economical solution; however, limited work has been carried out on the potential life cycle cost savings of green roofs in arid climates. This paper present costs savings by green roofs in arid climates. The model accounts for energy savings, structural considerations as well as other variables. Detailed thermal simulations for various configurations of green roofs are performed to assess energy savings using DesignBuilder. Experiments are performed for a two story residential building in Egypt with a base case control that uses a traditional roof meeting standard model energy codes. One local sub-climatic zone was simulated while changing the thickness of the green-roof soil, the conductivity of the green roof and building aspect ratio. Costs for green-roof saving potentials were estimated according to Egyptian electricity consumption calculator, other parameters as retrofit potential and structure allowances to withhold the required layers with different thicknesses. The results demonstrate the economic benefits of using green-roofs under different design situations and provide guidance for the selection and design of green-roofs systems in similar climates. Savings varied from 15-32% compared to traditional and un-isolated roofs. It was also found that reducing soil thickness to 15 cm results in 15% annual savings, Moreover, conductivity of soil has significant impact on amount of savings. The research shows that the most energy saving realized when the aspect ratio of the building is 1:1.5.

Since construction is considered as one of the main sources of environmental pollution in the world, the level of knowledge and awareness of project participants, especially project managers, with regards to environmental impacts of construction processes needs to be enhanced. This paper aims to assess the most common environmental impacts due to the construction process in Malaysia. To achieve this aim, a structured interview was conducted with an expert panel group in Malaysia. Experts were invited to identify the frequency and severity of environmental impacts caused by construction processes in residential buildings. It was found that ‘Transportation Resource', ‘Noise Pollution', and ‘Dust Generation with Construction Machinery' are the greatest environmental impacts in Malaysia respectively. The results of this study are useful for construction managers and other participants in construction sites to become aware of construction processes impacts on the environment.

Researchers at Iowa State University have investigated several alternatives for the stabilization of granular shoulder materials. Soybean oil soap-stock (SOS) appears to be an effective and environmentally friendly treatment. The stabilizer used in field studies is a proprietary formulation of SOS called "DUSTLOCK." SOS is a by- product of the refining process of soybean oil. Being a by-product, it is relatively inexpensive, though several other uses exist. It is also attractive because it can be applied at ambient temperatures with distributor trucks and fits the equipment and labor skill set that is available in many state Department of Transportation (DOT) shops and local jurisdictions. SOS shows promise in certain cases. In previous testing, some sections performed very well. Continuing research is investigating the traffic levels and materials where SOS stabilization can be both successful cost-effective. Iowa State University researchers are working with Iowa Department of Transportation (IDOT) personnel to investigate application techniques and alternative equipment configurations so that SOS might be used in as many situations as possible. In the summer and fall of 2011, ISU researchers worked with IDOT to test application procedures in locations with differing traffic levels and using various application techniques. Ongoing research is monitoring the performance of the stabilized shoulders over time.

Earthwork activities are a major part of many construction projects. They are typically performed by heavy-duty construction equipment that consumes large quantities of diesel fuel and results in large quantities of carbon dioxide (CO₂) emissions. An estimating tool is needed to accurately assess the economic, energy, and environmental impact of earthwork activities that utilize heavy-duty diesel equipment. This paper presents the framework for a model that can be used to estimate the production rate, unit cost, activity duration, total activity cost, total fuel use, and total CO₂ emissions for earthwork activities. A case study and sensitivity analysis for a bulldozer performing a bulk excavation activity is presented. Results indicate that there is little difference in the economic, energy, and environmental impact of sand and gravel, sandy clay and loam, and common earth but clay has a substantially higher impact than the other three soil types.

There are currently many discussions on sustainability emphasizing the needs of infrastructure, lower energy consumption, durability, and recyclability. In the United States, residential buildings consume 22% of the country's total energy and also are responsible for 22% of carbon dioxide emitted to the environment. The main objective of this research is determining the potential energy savings in residential buildings in the U.S. To find energy savings potential, the Residential Energy Consumption Survey (RECS) was used. This dataset provides general information on condition of appliances and buildings components as well as energy consumption in residential buildings. Based on RECS, this study took a broad look at energy savings potential for space heating, air conditioning, refrigerators, freezers, and lighting in residential buildings. Results of this study indicate that 29% and 19% of energy used for space heating, space cooling can respectively be saved by improving building components such as glasses and thermal insulation. In addition, results of this study show that 5% of total electricity used in residential buildings is delivered to nonefficient refrigerators, freezers, and light bulbs. By realizing the aforementioned energy savings in buildings, not only will consumers pay less money for their energy bills, but also greenhouse gas emissions from buildings can be reduced. Also, results of this study can help decision makers allocate tax credits for different products in such a way as to encourage actions targeting higher energy savings.

The Solar Decathlon is a two year, international project where university students compete to design, build, and test energy-efficient, net-zero homes. By definition, net-zero energy houses annually produce as much electricity as they consume. The 2011 Solar Decathlon, held in Washington D.C., had 19 university teams from around the world. Unfortunately, many past Solar Decathlon houses have traditionally been very costly. However, the 2011 Solar Decathlon was the first competition to have an affordability contest. The affordability contest required each home to be valued under an estimated builder's cost of $250,000, forcing the teams to select economically feasible solutions for creating net zero energy houses. Finding super-efficient, solarpowered, and affordable houses can be done by evaluating the contests associated with the Solar Decathlon 2011. The main cost-effective and energy saving components were discovered by researching final competition scoring of each specific contest. Heat pump water heaters, properly sized photovoltaic arrays, and HVAC systems with proper dehumidification were the main findings of this research. Fortunately, all of these findings can immediately be implemented into the design of net-zero energy housing with off-the-shelf products.

Greenhouse gases and higher energy consumption due to industrial activities have led to serious problems such as global warming. To solve this problem, various acts are adapted and many researchers have conducted studies to propose improvements. Furthermore, the construction industry has embarked on many studies to achieve sustainability of various resources required for construction projects. Most Life Cycle Assessment models developed in previous researches for use in evaluating an environmental performance, however, were developed for a manufacture and maintenance phase of construction projects. Therefore, it is difficult to evaluate the environmental performance in a construction phase. Generally, the environmental performance in the construction phase depends on construction methods used. Therefore, in this research, to evaluate the environmental impact of the construction phase, the construction methods based on the construction process of residential buildings were reviewed. Moreover, an evaluation model for the carbon dioxide emission of the construction methods was developed based on the LCA methodology. Through the developed model, eco-friendly construction methods that can enable carbon dioxide emission reduction are expected to be selected.

Typical higher educational organizations like universities and colleges are long-lived institutions with large campuses. These organizations inevitably have significant impacts upon the environment and ought to take more responsibilities on sustainability for their communities and regions. This paper explores the means and methods to apply knowledge management (KM) to support Capital Project Offices (CPO) at higher education institutions in the course of sustainable construction. While knowledge is generally regarded as a necessary foundation for sustainability innovation, its capturing and reuses has not been fully materialized in CPO organizations. One of the challenges is to understand and describe the types of sustainability knowledge of importance to CPO organizations. To this end, the authors conducted an in-depth case study at the University of Washington to explore its CPO personnel's perceptions on KM as it relates to sustainable construction. Survey questionnaire and interview were administered to collect data for the case study. In particular, a web-based KM system was used to help situate research participants in a pseudo knowledge capturing and sharing scenario to facilitate data collection. Research findings depict the status quo of KM in the case study CPO, point out barriers of the current practices, and based on the findings, a classification system tailored for CPO organizations to describe their sustainability knowledge is proposed.

The main goal of U.S. Green Building Council (USGBC) is to create prosperous and sustainable future through cost-efficient and energy saving green buildings. Several initiatives and steps have been taken by the USGBC and the construction industry to promote sustainable, cost-efficient construction practices. To stop further depletion of fuel energy sources, sustainability has been implemented on a large scale in such institutional buildings as schools, colleges, universities. Green buildings are designed to reduce operating costs by reducing energy consumption, but literature has shown that green buildings can cost more than non-green buildings. In this study, data were collected on construction cost and schedule for 30 Green School Buildings (GSB) and 30 Non-Green School Buildings (NGSBs) of the Clark County School District (CCSD) in Nevada. Statistical tests were performed to determine whether there was a significant difference in construction cost and time of completion between a GSB and an NGSB project. The results showed that the construction cost per square feet of a GSB is significantly higher than that of NGSB. In addition, the construction duration in building a GSB is significantly greater than that of an NGSB. The findings of this study will benefit further research on life-cycle cost analysis of green and non-green buildings.

Buildings are one of the major consumers of energy in the U.S. Both commercial and residential buildings account for about 42% of the national U.S. energy consumption. The majority of commercial buildings energy consumption is attributed to lighting (25%), space heating and cooling (25%), and ventilation (7%). Several research studies and industrial developments have focused on energy management based on maximum occupancy. However, fewer studies, with the objective of energy savings, have considered human preferences. This research focuses on office buildings' occupants' preferences and their contribution to the building energy conservation. Accordingly, occupants of selected university campus offices were asked to reduce lighting levels in their offices during work hours. Different types of information regarding their energy consumption were provided to the occupants. Email messages were used to communicate with the occupants. To monitor behavioral changes during the study, the test bed offices were equipped with wireless light sensors. The deployed light sensors were capable of detecting variations in light intensity, which was correlated with energy consumption. The impact of different types of information on occupant's energy related behavior is presented.

Uncertainty estimate of embodied energy of construction materials is a common issue in life cycle assessment (LCA) of a construction product or system. This paper introduced a new method to improve existing uncertainty estimate method using Data quality indicators (DQI). By using analytical hierarchical process (AHP) to weight DQIs the proposed new method is able to add appropriate weighting factors to corresponding DQIs. The results indicated that the proposed method can generate improved estimate of embodied energy of construction materials compared to unweight DQI method. A bridge case was used to show how the improved method affected the LCA decision making.

With growing concern about global warming and climate change, the construction industry, as a major contributor to greenhouse gas (GHG) emissions, has begun to realize its essential role in improving the environment by reducing emissions through the life cycle of buildings and infrastructure. In the meanwhile, despite conflicting scientific evidence as to the severity of GHG emissions' impact on climate change, the insurance industry has more of an incentive than any other industry to catalyze upon global action to promote sustainability. In the long term, these strategies could help mitigate the risk of catastrophic natural hazards that would affect many insurance lines, including property and casualty, business interruption, health, and life. Although green insurance is a relatively new concept, first started in 2006 by Fireman's Fund, insurance companies has provided a variety of products or services covering renewable energy, energy efficiency, and green buildings, either new or upgrades of existing buildings to a more resilient status following a loss. However, with government entities seeking to launch incentive-based regulations and bidding standards for reducing carbon footprints, insuring against the risk of discrepancy between the actual and expected performance of GHG emissions during construction is another aspect that is often overlooked. Drawing an analogy from the construction professional liability insurance, this paper explores the possibility of introducing emissions liability insurance, an innovative insurance product designed to manage embodied carbon in the building process. This paper initially elaborates on the role of insurance in sustainability risk management and follows this with an investigation on the Insurability of GHG Emissions Liability. Finally, a conceptual model is presented to illustrate how to utilize emissions liability insurance to guarantee the performance of GHG emissions during the construction phase.

The construction industry has a significant environmental footprint, especially in terms of greenhouse gas emissions and energy consumption. Substantial amounts of greenhouse gasses and non-greenhouse gasses that have an indirect radiative effect are emitted from construction activities and processes and during production, installation, maintenance, and end-of-life disposal of construction materials. These emissions can be controlled and minimized by optimizing the utilization of construction resources. This includes the optimal utilization of the available construction crews and materials in such a way that reduces greenhouse gas emissions while minimizing construction cost and duration. Therefore, this paper presents the development of a building construction planning model that is capable of minimizing greenhouse gas emissions, construction cost, and construction duration, simultaneously. The model is implemented in three main steps: (1) analyzing the impact of construction activities and processes on global warming potential (GWP); (2) evaluating the impact of these activities and processes on construction cost and duration; and (3) optimizing the utilization of construction resources in order to facilitate the selection and implementation of the construction methods that reduces the GWP while keeping construction cost and duration to a minimum. An application example is analyzed to illustrate the use of the developed model and examine the relationships between all three planning objectives. The analysis of the application example demonstrated the capabilities of the developed model in controlling the global warming impacts from construction activities and processes. Furthermore, the examination of the relationships between GWP and construction duration and cost can help designers and construction professionals in making environmentally-conscious yet cost-effective decisions during building design and construction phases.

The paper explores minimum emission configurations in earthmoving and like operations, including quarrying and open-cut mining. Emissions data, based on field observations and available in the public literature, are used to derive operation configurations that lead to minimum emissions. Such configurations are compared with conventional minimum cost solutions in order to give guidance as to the best way to configure and manage earthmoving operations. Variables considered in the analyses performed include truck fleet size, truck capacity and loading, loader capacity and haul route parameters. It can be shown for certain assumptions and configurations that the minimum emissions per production solution coincides with the minimum cost per production solution. In such circumstances, managing earthmoving, quarrying and open-cut mining operations in conventional costefficient ways leads to least emissions; it also follows that not managing such operations in a cost-efficient way will lead to unnecessary emissions. The paper's derivations are original and will be of interest to those designing and managing earthmoving, quarrying and open-cut mining operations, particularly with reference to sustainability.

Construction operations are highly energy-intensive and generate a significant amount of air pollutant emissions, including carbon emissions. Controlling the operational efficiency of equipment is key to managing and improving the environmental performance of construction operations. However, efforts to improve environmental performance are limited due to the industry's lack of a practical method for monitoring the operational efficiency of construction equipment and related environmental performance. Currently available methods are costly or have compatibility issues. In this context, this paper aims to develop a monitoring system that ensures economic feasibility and compatibility, and that uses vibration signal analysis. First, the paper discusses the relationship between operational efficiency and environmental performance. Then, the paper presents a method for using vibration signal analysis to monitor the operational status of equipment. Finally, a case study of an excavator demonstrates the presented method's feasibility in a real-world operation.

Construction waste is a major source of urban waste received at many landfill sites around the world. A number of waste management methods have been in use to deal with the substantial amounts of various kinds of construction waste in order to relieve the heavy waste burden in many cities. To achieve sustainability in urban development, different waste management methods should be carefully examined taking into consideration various attributes, for example, financial cost, lost energy, and accessibility and reliability of technologies. In evaluating these attributes, some can be represented by numerical values while others expressed in linguistic variables due to the human being's inability to assess these complicated attributes. The utility-based model proposed in this paper enables computing with words without much loss of information, overcomes the gap between numerical values and linguistic description, employs utility functions to transform multiple scales of different attributes into a common scale for easy comparison, and finally chooses the appropriate waste management methods for different kinds of construction waste.

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System, developed by the U.S. Green Building Council (USGBC) and later adopted by the Canada Green Building Council (CaGBC), has been widely accepted by public and private owners. Nevertheless it has been proven that adherence to LEED requirements has various effects on construction worker performance and productivity, construction cost and schedule and the environment. As a result, this limits the extent to which industry professionals apply the LEED principles, and are faced with difficulties in selecting the credits to be implemented in LEED certified projects. Therefore, there is a growing need to improve the sustainable goals by optimizing the LEED credit selection process to gain higher efficiency and productivity, which would result in increased popularity among contractors and design consultants. It has been identified that each LEED credit would have a different impact on cost, schedule, environment and the construction productivity. A considerable amount of literature has been published regarding these impact areas and it is clear that the impact is different from each credit and each project. However, very little research has been carried out that considers the combined effect of the identified factors. This paper describes the development of a multi-criteria prediction model that has the ability to model phenomena with significant uncertainty in inputs and multiple criteria such as project cost variation, the environmental impact, the impact on schedule and the impact on construction productivity. This simulation tool can be used by the design team at an early stage of the design process to optimise the benefits and minimise the negative impacts of LEED implementation in a new construction project.

Water distribution systems play an important role in supplying water to consumers in a timely and efficient manner. The importance of such systems, in addition to the complexity of their design, has led to extensive research in the area of optimal design of water distribution networks. Traditionally, only system costs are considered in design with few models incorporating environmental impacts. This paper presents a model for designing sustainable Greenfield water distribution networks with the objectives of minimizing life cycle costs, life cycle CO₂ emissions, while ensuring hydraulic reliability for the life time of the system. The model integrates a multi-objective genetic algorithm with water network simulation software, EPANET, using Visual Basic for Applications (VBA). A traditional benchmark water distribution network is used to demonstrate the model. Six scenarios have been developed to test and validate the model for a variety of objectives with different constraints. Trade-offs between life cycle costs and life cycle emissions, along with hydraulic reliability of the system are illustrated. The result of this research is a model that can be used to design large, sustainable and reliable water distribution networks.

Photocatalytic compounds such as titanium dioxide (TiO₂) can be used to construct pervious concrete pavements that can trap and degrade organic and inorganic particles in the air. Photocatalytic pervious pavements transform harmful pollutants such as nitrogen oxides (NO_x) into nitrates salts when subjected to UV light from the sun purifying ambient air from vehicle emissions. In spite of these benefits, an increase in nitrate levels may cause eutrophication. The objective of this study is to evaluate the amount of nitrates released due to pervious photocatalytic concrete and to assess potential eutrophication issues. To achieve this objective, pervious concrete samples were tested in the laboratory for photocatalytic NO_x reduction efficiency according to JIS standard. The test was performed using an innovative lab setup and conducted under different environmental and operational conditions including flow rate, UV intensity, temperature, and relative humidity. After testing, samples were washed with deionized water (DI) to collect the nitrates deposited on the surface. The concentration of nitrates collected was measured using a colorimetric method known as cadmium reduction. Results showed that photocatalytic pervious concrete is capable of purifying ambient air from NO_x. Results also showed that the concentrations of nitrate deposited on the surface are low and will not cause eutrophication problems.

Fly ash, a by-product of coal burning electric power plants, has been used as a partial replacement for Portland cement in concrete for over 70 years. Currently, the typical replacement range is limited to 15 to 25 percent. Although the use of fly ash in concrete has increased over the last 20 years only about 20% of fly ash generated is used in concrete. Recent interest in increasing the sustainability of concrete has resulted in the study and use of high volume fly ash (HVFA) concrete, which can contain up to 50% or more fly ash replacement. In this study, a locally produced Type C fly ash was used to examine the practicality and sustainability of using HVFA concrete for sidewalks at a university campus. Eight mortar mixtures, containing 0, 20, 60 and 90% fly ash replacement were tested for their strength development characteristics. The target mortar strength was 27.6MPa (4000 psi) at 28 days based on guidance provided by a local concrete contractor. Hydrated lime was added to mixtures containing 60% and 90% fly ash, to determine the ability of lime to enhance the chemical activation. Following the outcomes of compressive strength testing an overall life cycle assessment (LCA) was conducted using SimaPro7 software to determine the environmental impacts of concrete made with these increasing amounts of fly ash. The compressive strength test results showed that mortar mixtures containing 60% fly ash and lime can be designed to fulfill the requirement of strength suitable for concrete sidewalk construction. The LCA indicated that replacing cement with 60% fly ash has significant impacts on reducing embodied carbon dioxide emissions and raw material consumption in the concrete manufacturing process.

Motivated by the need to address challenges of global climate change, this study develops and implements a project based life cycle assessment framework that can be used to estimate the carbon footprint for typical construction work-items found in highway reconstruction and rehabilitation projects. The proposed framework considers the life cycle emissions of products and processes involved in the raw material acquisition and manufacturing phase, and the pavement construction phase. It also accounts for emissions due to vehicular use and maintenance operations during the service life of the pavements. The framework introduces methods based in life cycle assessment to (i) develop project emission inventories for highway construction, rehabilitation and maintenance projects, (ii) analyze the inventories to calculate project level construction emission estimation metrics. Fourteen highway construction and rehabilitation projects in the State of Michigan were used to implement the method and validate the analysis approach. In addition, the paper introduces the Project Emissions Estimator (PE-2) - a web based tool that can be used to estimate and benchmark the CO₂ footprint of highway construction projects. The contribution of this research is that it furthers our understanding of pavement life cycle assessment methods while providing an emission estimation tool that can be used by decision-makers to monitor and assess project emissions.

Sustainable development is Qatar's main national goal. The fact that Qatar has secured the World Cup bid for 2022 will make it the first Arab country to host the world cup. This honor and Qatar's plan to advance its development has led the state to start upgrading its entire transportation infrastructure. Qatar's commitment to sustainability and the state's upcoming investments in the transportation sector has led the authors to investigate current transportation sustainability assessment systems, which can be transferred to Qatar. A thorough literature review revealed that the current initiatives have a number of limitations that render them inapplicable to Qatar. This paper presents these findings and suggests the main features of a sustainability rating system applicable to Qatar. This will be the first step in developing the Qatar Transportation Sustainability Assessment System (QTS).

The concern of environment and sustainable development has been increased recently. These problems force the countries to adopt a number of policies that enhance energy efficiency and apply baseline parameters in accordance with international standards. Green building has now become a forefront of sustainable development in this century that takes the responsibility for balancing long-term economic, environmental and social health. It offers an opportunity to create environmentally efficient buildings by using an integrated approach of design. The energy efficiency as a key performance criteria group for sustainable buildings is investigated in this paper. In this study the most important criteria of energy efficiency are identified and based on Iran Renewable Energy Organization's expert's opinions, the most common renewable energies are compared, as well as, their feasibility to implementation in urban areas and buildings are studied. As the results of this research, solar energy (active and passive form) has the highest priority, advantage, and application for using in urban areas and buildings in Iran. However, passive solar energy has more application, but there are some obstacles for developing this system.

Distributed power generation is growing dramatically in recent years. Combined Heat and Power (CHP) technology which allows for portfolio optimization of clients needing both heat and electrical energy, is one promising technology. Compared to separate fossil-fired generation of heat and electricity, CHP generation through fuel cells may result in primary energy conservation, varying from 10% to 30%, depending on the size and efficiency of the cogeneration units. Fuel cells stand out for their reliability, efficiency and ease of deployment. Fuel cells have already been deployed, but are still in experimental stage. This paper investigates the challenges and possibilities of fuel cells for use in the residential sector, through literature review and the lessons learned from a current design, simulation and feasibility study completed at the Georgia Institute of Technology. We find that while the initial investment necessary for fuel cell power at the residential level is still very hefty, rising prices of electricity and inefficiencies in distribution are bringing payback periods closer to other solutions such as photovoltaic power generation. Fuel cells can produce enough power for most residential needs and can be supplemented by the grid, or other sources, to cover peak power demand. They can run non-stop at full power creating excess electricity in non-peak periods that can be sold to utilities through net-metering and buy-back programs. Their equity payback periods are also getting closer to 16 years, at current electricity prices and inflation.

The objective of this paper is to propose an integrated assessment approach, which is based on the broad interdependencies of our infrastructure systems and built environment, for better evaluating the construction industry, and its processes, within the context of sustainable development. The available evaluation tools and techniques focus mainly on assessing the environmental and mechanical aspects of construction. The problem is even compounded with the: (1) fragmentation and stratification of the construction industry; (2) disconnection between the industry and its consumers due to stark asymmetry of information, cultural differences, and inefficient contractual arrangements; and (3) recent urban governance trends that promote regionalism or liberal expansionism. To fill in this critical knowledge gap, the proposed framework creates a holistic framework to study, simulate, analyze, and predict over time the civil infrastructure resource dynamics within the broader socio-economic structures of its stakeholders.

In line with current trends of measuring the sustainability in built environments, there has been an increasing interest in the environmental assessments of green transportation projects. As a result, a number of environmental assessment tools are used, or are being developed to evaluate the sustainability level of a transportation project. Thus, the use of quantitative environmental assessment tools for transportation projects is expected to increase, making it relevant to ascertain their status of development process. This study aims to apply a unified thematic framework to compare the sustainability rating systems for transportation projects. In an effort to do so, this paper describes and compares various different tools used for the quantitative environmental assessment of transportation projects. Selected here are four quantitative assessment tools, which measure the sustainability of a transportation project or program in the United States over life cycle. The purpose of this paper is to provide all thresholds, such as planners, contractors, state officials, and environmentalists, with a better picture of the situation and indicate the benefits and shortcomings of the tools, but not to prioritize the four different tools to determine which the best system is.

Going green is a mega trend in the construction industry and is incorporated in the project's delivery, front-end design, constructing process, contracting negotiation and facility operation. Such a green trend is also certified as a huge benefit for practical investors and debated in previous literature. However, the value creation path, from initiating a green concept until gaining economic payback, is still unclear and has only been investigated a few times in the construction industry. Studying such a green value creation chain can significantly help construction firms make wise decisions prior to investing any green business. The study also facilitates the understanding of key management issues when a construction company transforms into green business, such as pricing strategy, cost control, new market entry, and corporate financing. To fulfill these aims, this research conducts an empirical regression analysis based on 22 public firms in the US construction industry. A stepwise regression model tests firms' financial performances including Economic Value Added (EVA) and six accounting measures. The proposed result shows that embracing green business could create more value for construction companies through two chains: (1) by creating a higher operating profit margin; (2) by managing assets more efficiently with a higher turnover rate. Possible explanations and managerial implications are discussed at the end.

The ever growing population demands more buildings, greater infrastructure which in turn demands more use of resources. This growing use of resources causes depletion of the current energy and water reserves. Pakistan in the global context stands amongst one of the most water stressed nations and if the current water usage pattern continues, it would be amongst the water scarce nations by year 2030. The depleting water resource is an alarming situation for the entire nation. The growing infrastructure increases the amount of run-off water along with increased demand of water supply. Sustainable construction practice is a way to address the environmental, economical and social issues with significant focus on water efficiency. In order to assess the water savings by water conservation a framework has been developed to identify means and methods for reclamation of storm water. A case study of university campus is selected to assess the impact and contribution of water reuse on fresh water savings. The campus complex is divided into smaller zones based on their functionality and varying surfaces. Each zone is evaluated for the amount of rain and storm water generated using the rational method to calculate the runoffs. The result confirmed that storm water management can facilitate significant fresh water saving. The study in the end proffered the measures to reuse the non-potable water by efficient technology and human behavior.

To improve first year engineering students' understanding of the design process, a collaborative bridge design project is given to Architectural Engineering students during their first year at Penn State. This paper examines the benefits of reverting to traditional physical prototyping techniques for students to better understand the design process and how to compose and interpret design documents. Students create a preliminary set of design documents, exchange documents with a group of their peers, physically build a prototype of their peers' design, and synthesize design feedback. This process of generating feedback from another group's design through building their bridge benefits the students by allowing them to improve their design document comprehension skills and by gaining formative design feedback from another group of students in their class. After the prototyping activity: students were more likely to recognize areas of deficiency of their own work as well as the work of others; they could comprehend their peers' work well enough to accurately predict the primary design intent of their peers' designs; and the quality of the design documentation submitted improved over prior semesters that did not involve a prototyping design review activity. While this exploratory research suggests several distinct learning benefits based on the obtained data, it was also found that students' self-reports suggest that they do not necessarily recognize the learning benefits from this type of prototyping activity.

This work is part of a regional initiative to build training and employment services into a career pathways system for the green building industry sector, with a particular focus on construction and retrofitting towards more energy-efficient buildings, and installation of alternative energy systems. It addressed the challenges of collecting and disseminating relevant information for innovative technologies and sustainability in a format that supports systems integration. The research team developed a collaborative content authoring and dissemination portal as part of an U.S. Department of Labor Energy Training Partnership grant with participation from Virginia Tech, regional community colleges, certification training institutions, and other industry stakeholders. The paper discusses the process of collaborative content collection and authorship, the potential of open-source software for content management, the development and implementation of envisioned concepts into a single online portal, and the feedback processes through multiple channels from various program participants. While comparing the resulting software implementation with the initial project goals, this paper provides recommendations on how to sustain an online project and the currentness of its content. Further work will examine the adaptability of the educational collaboration portal to address specific pedagogical formats, language barriers, and interoperability with recognized software formats.

Serious games are computer games designed for education and training purposes. A large number of investigators have studied the effectiveness of serious games. The results of the studies show that only games that incorporate sound educational principles and have appropriate user interfaces are effective tools for learning. A serious game for construction planning and scheduling education must provide an authentic environment for gameplay. To achieve this requirement, the game environment must be created from CAD drawings of a real project. The game engine must have components for providing timely scaffolding and support to the user. Storing the vast amount of data for a real project requires data structures optimized for fast rendering at the same time easily accessing and manipulating building elements and element data. This paper discusses a game engine developed for creating construction planning and scheduling educational games. The game engine is designed from scratch for performance and flexibility. It includes a component for directly importing data from a Revit model for building the game environment, interfaces Microsoft Project for scheduling, includes a feedback module, and a scoring system for measuring user performance.

In an email from August 20, 2011the Chief Editor of the Journal of Construction Engineering and Management wrote that the main criteria of an acceptable paper review were timeliness, objectivity, factuality, fairness, thoroughness, and professionalism. A request for clarification about the definitions of fair, objective, and thorough did not receive a response. It provided the latest impetus to get an article on this subject published after having failed multiple times. The paper explores whether the ambiguous and scientifically irrelevant assessment criteria effect the scholarly quality of the journal itself. It further reviews the performance of the journal measured by its impact factor. A discussion of requirements for scholarly work defined by qualified researchers in construction engineering and management follows a brief initial review. The paper proceeds with an evaluation of scholarship in some recently published articles. Finally, the paper offers a framework to serve as a transparent standard for reviewers' assessment of draft papers' scientific rigor. The hypothesis that a lack of consistently high scientific standards applied by its reviewers has a bearing on the quality of a scholarly paper is tested. With support from the literature it will be shown that measures such as fairness, thoroughness, and objectivity have no place in evaluating a submitted paper's scientific quality.

As the construction industry experiences rapid advancement and expansion in both quantitative and qualitative perspectives, it demands a better educated and highlyskilled workforce. The industry looks for professionals who have a solid foundation in the technical and managerial principles so that they can become industry leaders in the future. Therefore, it is a critical matter to develop construction management graduate programs in the right direction. A graduate construction management program can be designed to incorporate a broad range of subjects including construction management, construction technologies, and general management areas to develop well-balanced construction professionals. However, few studies were performed previously on the graduate education in construction management and the operation of graduate programs. Thus, a study is necessary to evaluate current construction management programs at the graduate level before discussing how we can develop them further. This study aims at identifying leading construction management programs in this nation and investigating how they manage and operate graduate programs. The authors chose the leading graduate programs by selecting the top 100 universities from the U.S. News and World Report, the most relevant ranking source for this study. The authors have developed a survey questionnaire, and the major findings obtained from surveying 15 schools are illustrated and explained in details in this paper.

This qualitative study will analyze the motivations and expected outcomes and identities of a construction career as seen by a unique cohort of engineering students—volunteers of Engineers Without Borders-USA (EWB-USA). These volunteers are a diverse group who defy the stereotypes and statistics of the construction profession by displaying near balanced ratio of males to females. EWBUSA is a service organization comprised of student and professional volunteers. Unlike most engineering and construction organizations, it experiences 30-40% female membership. As such, it has been chosen as a strategic research site to investigate the motivations and expected outcomes of EWB-USA volunteers. This research project held focus groups with female and male students attending the 2011 EWB-USA conference. Qualitative analysis of the discussion supported the hypothesis that EWB-USA volunteers report altruistic motivations for entering engineering than do their non-volunteer peers. In addition, it highlights different motivations amongst males and females, with females citing mentorship and a sense of community frequently, whereas the male groups cited patriotism and travel. The implications of these findings may offer suggestions to help attract and retain women in engineering, including emphasizing humanitarian aspects of engineering and developing mentorship programs.

Competencies well-recognized by the National Academy of Engineering, the American Society of Civil Engineers, and the ABET Engineering Accreditation Commission all illustrate a broad set of skills required by the twenty-first century engineer. However, while these bodies challenge construction engineering programs to inculcate these competencies in their graduates, they do not provide the pedagogical tools needed to develop these competencies. By examining two case studies, this paper demonstrates Engineering Projects in Community Service (EPICS) as a curricular structure that provides considerable opportunities to develop these important proficiencies. The case studies are two projects from one large, multidisciplinary, vertically-integrated student design team. One project focuses on sustainable and energy efficient housing for Habitat for Humanity (HFH) in Indiana while the other project focuses on affordable houses for HFH in Hinche, Haiti. While these projects are dramatically different in their setting, they both provide a unique opportunity for students to develop a broad set of professional and technical skills.

Education is crucial to a safe and healthy working environment in construction and engaging students in the construction engineering and management programs in this very important subject is the catalyst to the success of safety education. This paper discusses the evaluation of an innovative learning assessment tool, Safety Inspector, for the education of construction safety. Safety Inspector is a 3D video game previously developed to provide a "safe" environment that engages students in recognizing comprehensive hazards, evaluates student performance, and enhances student learning interests. Evaluation strategies developed in the research take into considerations student learning objectives for construction safety, limitations of available assessment resources, logistics of the course, signals that reflect underlying cognitive learning processing, and statistical validity requirements. To implement the evaluation, game-based and paper-based tests were both administered for the experiment with a follow-up questionnaire in an undergraduate class at the University of Washington. Some patterns were identified as a result of the evaluation. The major lesson learned is that when the hazard recognition tasks are presented similarly in different test modes, testing scores could be more statistically relevant. However, certain types of hazards are difficult to identify in the game-base test because they require the change of viewing angles that do not naturally occur in a virtual model.

The construction field is dynamic and dominated by complex, ill-defined problems for which myriad possible solutions exist. Teaching students to solve construction-related problems requires an understanding of the nature of these complex problems as well as the implementation of effective instructional strategies to address them. Traditional approaches to teaching construction planning and management have long been criticized for presenting students primarily with well-defined problems - an approach inconsistent with the challenges encountered in the industry. However, growing evidence suggests that employing innovative teaching approaches, such as interactive simulation games, offers more active, hands-on and problem-based learning opportunities for students to synthesize and test acquired knowledge more closely aligned with real-life construction scenarios. Simulation games have demonstrated educational value in increasing student problem solving skills and motivation through critical attributes such as interaction and feedback-supported active learning. Nevertheless, broad acceptance of simulation games in construction engineering education remains limited. While recognizing benefits, research focused on the role of simulation games in educational settings lacks a unified approach to developing, implementing and evaluating these games. To address this gap, this paper provides an overview of the challenges associated with evaluating the effectiveness of simulation games in construction education that still impede their wide adoption. An overview of the current status, as well as the results from recently implemented Virtual Construction Simulator (VCS) game at Penn State provide lessons learned, and are intended to guide future efforts in developing interactive simulation games to reach their full potential.

This paper shows how problem-based-learning (PBL) and learning-through-service (LTS) can provide a strong framework for fostering students' adaptive expertise, flexibility, creativity, innovation, and passion in the classroom. Mississippi State University (MSU) represented by its Civil and Environmental Engineering Department (CEE) is currently in the design-development stage for the construction of a new Civil and Environmental Engineering Complex (CEEC). CEE is garnering a new focus on sustainability with special emphasis on environmentally responsible design, construction, and operation of constructed facilities. To this end, the authors have mentored a group of 22 undergraduate junior students under the High Performance Sustainable Construction class to provide a comprehensive Leadership in Energy and Environmental Design (LEED) analysis for the new CEEC using the 2009 Reference Guide for Green Building Design and Construction, the student work shows that CEEC can possibly earn up to 74 points to acquire a Gold LEED Certification. This study shows that PBL and LTS can enhance students' abilities of understanding and solving real world civil infrastructure problems and challenges. Also, this student-driven teaching approach instills a creative learning environment, understanding of the surrounding world, and a sense of social responsibility.

Large class-size teaching has traditionally relied on lecturing in theatre style spaces with students transcribing what the teacher writes on the blackboard or projects onto the wall. Such lectures are commonly supplemented with tutoring sessions in which students are helped to complete homework assignments followed by graded tests. However, research has shown that there is very little that the students learn beyond taking tests on narrow technical topics. The construction industry, however, is asking for engineers with skills that cannot be taught using this lecture based approach to teaching. This paper presents the results of a pilot study designed to evaluate the concept of formative assessment as a means to teach a large undergraduate class on construction engineering. The paper's focus is on sharing the experiences with an instant response e-learning tool, Poll Everywhere, and the effectiveness of engineering sketching as an educational tool. This pilot study found that by applying known pedagogical models and resources, even large classes can be turned into active learning experiences that benefit every student.

This paper addresses the implementation of a teaching module related to social sustainability, focusing on the planning and design phases of construction projects. The target population for this study included 74 seniors and 40 graduate students in Sustainable Construction and Infrastructure courses offered by three firsttier academic institutions during the Fall of 2011. The module proposed here provides the foundation for discussing four social sustainability conceptual areas: community involvement, corporate social responsibility, social sustainability, and safety through design. The implementation requires four steps. The first step uses a survey to assess the students' previous knowledge of social sustainability. The second step focuses on learning about social sustainability through a mini-lecture and a class discussion, emphasizing that this construct involves multiple perspectives. During the lecture, the students then provide specific social sustainability examples for each of these four conceptual areas. The third step involves students learning how to create concept maps based on Novak's technique. Finally, the students create individual concept maps that are subsequently used as post-assessment tools, identifying the knowledge they have gained. The preliminary results indicate that the module provides a platform for increasing student awareness that sustainability involves more than the green features of a facility.

Supported by a National Science Foundation, Pan-American Advanced Studies Institute (PASI) grant, two expeditions of multi-disciplinary researchers were made to the Andes Mountains of Perú and to the city of Cusco to reverse engineer the Inka Road. The objective was to identify sustainable engineering practices that apply to modern practice. Travel to the Inka Road in the highlands of South America is difficult; thereby creating a challenge for bringing together students, technical experts, and other interested parties for real-time information sharing and collaborative research. In order to meet this challenge, the research teams joined forces with the Smithsonian Institute's National Museum of the American Indian and streamed live interactive broadcasts from the cordillera of Perú to audiences in Washington D.C. Pioneering the use of satellite-based audio and video communication equipment, the on-location researchers were able to share and explain the physical conditions of the Inka Road with museum visitors and experts in real time. Participants at the Smithsonian were able to ask questions in an interactive, 2-way dialogue with the field teams. On-site researchers were able to inquire of experts, located in different parts of the world, questions regarding possible Inka findings. The broadcasts from the Inka Road provide a proof of concept example of tele-engineering from a very extreme environment. This paper explains the tele-engineering concept and how it was used to help reverse engineer the Inka Road. This approach has applicability in designing and constructing projects in remote locations where subject area specialists may not be locally available, but off-site, engineering experts can contribute to the project using tele-presence.

As the construction industry continues to grow globally there is an increased demand for graduates who possess the skills necessary to work in inter-disciplinary and multi-cultural teams. These skills, while fostered in the classroom, require a contextual learning environment to allow students to personalize the information. Using a constructivist approach allows these skills to be acquired and improved over time. This type of learning environment was created during a field research project supported by a National Science Foundation, Pan-American Advanced Studies Institute (PASI) grant, where two teams of multi-disciplinary researchers traveled to areas of Perú to reverse engineer the Inka Road with the objective of identifying sustainable engineering practices. The teams consisted of engineers, architects, constructors, archeologists, anthropologists, historians, a music culturist, and a high school student. Additionally the team members were from three different continents representing seven different countries and were a mix of faculty, graduate students, undergraduate students, and industry professionals. The work undertaken required documenting engineering and construction practices of the ancient Inka Road and its associated structures, to include hydraulic channels, terraces, retaining walls, storage areas and ritual sites. While in the field the outcomes of the daily work was shared with an audience at the Smithsonian Institutes National Museum of the American Indian via live interactive satellite broadcasts. These broadcasts were also available over the internet. This required the teams to work cooperatively in an unpredictable physical and time constrained environment to ensure success of the broadcasts. Team members came to understand the challenges of working together with unfamiliar people speaking various languages and utilizing discipline specific terminology. This setting provided participants with the opportunity to develop a greater understanding of the skills required to be successful working in these types of teams. This paper examines the benefits, challenges, and opportunities of performing engineering research with inter-discipline, multi-cultural teams in a field environment.

Following disasters, housing is a principal component of economic and buildings losses. Traditional interim housing programs have been criticized for their inability to (1) adequately address the socioeconomic needs of displaced families; and (2) control expenditures. The objective of this paper is to present a new housing framework that can revolutionize the current understanding of post-shelter housing from an overly expensive, socially disruptive activity to a capacity building process. The proposed framework supports the development of a community-based housing response pool that can (1) transform the one-size-fits-all housing assistance to a customized need-tailored approach, while (2) supporting local businesses to recover. This paper presents the development of two key modules within the proposed framework, including (1) an automated data acquisition module; and (2) a data mapping module to match available housing characteristics and locations to fulfill the social, emotional, and economic needs of displaced families. Moreover, this paper discusses the need to develop (1) an IT-based collaboration system among multiple localities and agencies; and (2) a real-time housing procurement system. The proposed framework should prove useful to emergency management agencies in (1) utilizing available housing resources; and (2) quantifying the need to construct/install additional interim housing within the affected communities.

This study investigates the utilization of Geographic Information System (GIS) technology to rapidly disseminate damage and failure mode data related to wood-frame construction collected in the aftermath of the Tuscaloosa tornado on April 27, 2011. The City of Tuscaloosa was in the direct path of a major super cell tornado that bisected the city in a south-west to north-east direction with a half mile wide destruction path. Immediately after the tornado, forensic data collection activities were conducted. Forensic evidence was collected through both active and passive modes. Active data collection occurred at specific case study sites and along transects that ran approximately perpendicular to the direction of the tornado path. Passive data collection modes captured forensic evidence as researchers moved throughout the affected area. Tracking both the time and the location of field activities set the basis for the fusion of the collected data. Thus, by using the time of data collection, forensic data was correlated to a geo-location in full-day GPS track logs and uploaded in a GIS web portal. The web portal enabled 1) the geo-referenced analyses of the collected data, and 2) the rapid dissemination of the forensic evidence to the scientific community and to anyone with an internet connection.

Hazard management is not only associated with engineering and economic constraints, it is intricately tied to public policy and institutional control considerations. This paper shows how the authors have tied an ongoing research project for developing and optimizing tornadic risks in Mississippi with an integrated public policy educational plan at Mississippi State University that provide both university-based and societal-wide education. To this end, this paper discusses considerations for shaping public activity for natural hazards and man-made hazards through defining the basis for public intervention and the principles for public policy responses. The authors suggest public actions tailored to the unique properties of hazards, study public policy analysis for principles that might be useful in doing so, and explore implications of these circumstances for future education of professionals in public planning, engineering, and management. Such integrated approach is essential to develop effective, efficient, and equitable hazard mitigation measures.

Disaster resilience and recovery have been studied from a variety of perspectives including sociology, policy implementation, decision-making, engineering, geography and urban planning. For this reason, there is a wide range of definitions of resilience and recovery, and determining appropriate indicators of recovery and resilience is a challenge for both researchers and practitioners. We begin this paper with a discussion of the varying definitions of recovery, vulnerability and resilience and how they have been utilized in each field. In order to assess what indicators can be used to measure both resilience and recovery, we performed an in-depth content analysis on definitions and indicators from existing literature. We analyzed articles from 2000 to 2010 in four disaster-focused journals that include perspectives of engineers, social scientists, practitioners and economists. Articles were selected by a keyword search and analyzed for resilience and recovery indicators using an emergent coding scheme. We classified the indicators of community resilience into infrastructure, social, economic and institutional categories. Recovery indicators were categorized as social, economic, environmental and infrastructure. Researchers can use these results for future studies of causal factors and recovery indicators. Similarly, practitioners will be able to have a condensed opinion of experts in the field of disaster recovery and planning.

Natural disasters result in loss of lives, damage to existing facilities, and interruption of businesses. The losses are not instantaneous, but rather continue to occur until the community is restored to a functional socio-economic entity. Hence, it is essential that policy makers recognize this dynamic aspect of the incurred losses and make realistic plans to enhance recovery. However, this cannot take place without understanding how homeowners react to recovery signals. These signals can come in different ways: from policy makers showing their strong commitment to restore the community by providing financial support and/or restoration of lifeline infrastructure; or from the neighbors showing their willingness to reconstruct. The goal of this research is to develop a model that can account for neighbors' dynamic interactions by incorporating their signals in a spatial domain. A multi-agent framework is used to capture emergent behavior such as formation of clusters. The results from the model confirm the important role of spatial externality in agents' decision-making and the process of recovery. The results further highlight the significant impact of discount factor and the accuracy of the signals on the percentage of reconstruction. Finally, cluster formation was shown to be an emergent phenomenon during the recovery process.

This paper describes the results of a study on recent flooding problems that caused damages to the infrastructures in Northwest Indiana. Focused are the increased frequency of heavy storm events in the region and their resulting impact on the current sewer system. During the study, two phases of research were conducted. The first phase included the analysis of rainfall frequency in the area where floods recur on a regular basis. This paper describes the result of the rainfall frequency analysis over a 60-year time span from 1949 to 2008 using a non-parametric statistical method. The study area, Glen Ryan neighborhood, is located in the city of Gary in Indiana. The study used archived rainfall data available in National Climatic Data Center (NCDC) to fit updated probability distribution curve for the rainfall frequency analysis. The second phase included the impact analysis of the existing sewer system. The current sewer system in the study area was investigated in order to analyze the impact of the updated frequency of the heavy storms. This paper details the results of a series of simulation analyses followed by suggested management strategies to resolve the current flooding problems in the study area.

Human-induced hazards, such as terrorism, need to be considered in the management of infrastructure systems. Human-induced hazards, though, present data collection challenges that often force the use of other techniques, many times subjective in nature, for predicting the occurrence and magnitude of the hazard. No matter how human-induced hazards are dealt with in the management of systems, the need for predictions of the occurrence and magnitude of the hazard will be required to help allocate resources for infrastructure protection. The research described in this paper was an effort to show that agent-based modeling and simulation (ABMS) might be a computational technique that could be used to develop probabilistic models of the occurrence and magnitude of terrorist attacks in a community. The ABMS approach used in this study should be considered a prototype model for management of human-induced hazards. The objective of the research described here was to use a relatively abstract, resource-based, evolutionary agent model to examine if ABMS can be used to make predictions about the frequency, location, and magnitude of terrorist attacks. A major goal under this objective was to validate the prototype model in a preliminary manner. The agent model used is an extension of an evolutionary agent modeling technique that has been used in the past to study a range of social phenomena that emerge from relatively simple agents interacting in their efforts to obtain resources necessary for life. The basic approach in this paper of using ABMS to model human-induced hazards has been preliminarily validated in the sense that the attack magnitudes seem to be power-law distributed and attacks occur mostly in regions where high levels of wealth pass through, representative of transit routes and markets. The model developed in this study indicates that ABMS is a potentially viable approach to modeling socioeconomic-based infrastructure systems in order to deal with human-induced hazards. Other more domain-specific ABMS approaches are also possible and are briefly discussed.

A common dissent to alternative project delivery has been that the quality will not be equal to that of the traditional design-bid-build delivery method. One of the reasons for this concern is that the quality roles and responsibilities change when implementing an alternative delivery method due to early involvement of the contractor, a single contract for design and construction, and/or private funding being utilized for the project. While the fundamental quality activities remain the same, the overall project organization defining who is responsible for the activities and roles changes. Due to a lack of guidance and research the project quality organization shifts in an ad-hoc manner due to the time constraints of the project. This research determines the five fundamental quality management organizations based on the agency's quality responsibilities within the project quality management organization.

Condition states of civil infrastructure such as pavements and bridges are usually indexed on discrete scales, and Markov chain models are often used to estimate transition rates from one state to another, as well as sojourn times in any given state. Such models tend to assume homogenous transition rates between states, even though the models should account for heterogeneity to improve the accuracy of the predicted outcomes. Therefore, the objective of this study is to evaluate variations in model predictions when transition rates between condition states vary. Building on existing research, this paper considers a Monte Carlo simulation of a non-homogeneous Markov chain model for condition prediction of infrastructure systems. The method considers two scenarios (i) when transition rates are regressed according to a Weibull probability density function, and (ii) when transition rates are sampled as random values from interval estimates. For each scenario, multiple cases are further investigated to quantitatively describe variations in model predictions generated from variable transition rates. For the first scenario, simulations demonstrated that the accuracy of the model predictions is sensitive to the shape parameter for the Weibull distribution. Similarly, for the second scenario simulations illustrated that the interval estimates when chosen correctly can be used to establish confidence intervals for the transition rate parameter. Methods developed in this study can be used to test the accuracy of performance predictions for infrastructure systems, thus improving a decision-maker's confidence in using the models to optimize infrastructure maintenance schedules.

With the growth in Indian economy, major infrastructure development initiatives have been undertaken by the Governments at the central, state and local body levels. Transportation infrastructure projects recently undertaken in India have experienced large cost and time overruns. The development, construction and operation of the infrastructure facilities need a number of permits and approvals. These projects are more vulnerable to approval delays because they require various statutory and non statutory approvals and clearances during the development phase and project specific approvals during the implementation phase. This paper discusses the preliminary phase of the research to investigate and evaluate the impact of the various approval risks on the outcome of transportation infrastructure projects. Critical approval risks and risk sources have been identified through literature review and interviews with key experts in the various transportation sectors such as airports, metro rail and roads. The approval risks are structured in three levels through a risk breakdown structure (RBS). Approval risks are classified into development approval risks and implementation approval risks. Development approval risks are further broken down into statutory and non statutory approval risks. The identified approval risks will benefit the developers and project managers of the infrastructure projects to better plan infrastructure projects taking into account impact of these risks.

Traditional financing approaches, such as federal and state grants funded by taxation, are no longer sufficient to address the ever-growing need for sustaining and restoring the civil infrastructure in the U.S. Innovative financing approaches (such as novel public private partnership models, credit enhancement tools, and new bond instruments) have emerged to complement traditional approaches in sustaining and improving civil infrastructures. However, public support is critical to the success of innovative financing approaches, and thus an assessment of public perceptions is an essential consideration in the implementation of sustainable infrastructure financing policies. The objective of this paper is to analyze the four dimensions of public perceptions and their implications for policymaking as they relate to innovative financing of civil infrastructure. The factors affecting public perceptions include: economic conditions such as the gross domestic product and the unemployment rate; infrastructure conditions such as the percentage of infrastructure facilities in structurally deficient condition; and personal characteristics such as income, gender, and education. In this paper we assess how these factors affect the knowledge, awareness, and perceptions of the public regarding infrastructure development and financing. Statistical models are estimated using data collected from the general public in all 50 states in the U.S. through a web-based survey, data obtained from the scorecard of the U.S. infrastructure developed by the American Society of Civil Engineers and economic data obtained from the Bureau of Economic Analysis. Based on the findings of the statistical analysis, recommendations are provided to infrastructure sponsor organizations relating to educating the public to enhance public knowledge and awareness and designing financing structures that are consistent with the prevailing public perceptions.

On-site sanitation systems are vitally important infrastructure that is plagued by high failure rates. To address this issue, we conducted a literature review and solicited expert opinion on factors contributing to post-construction, design-life sustainability of on-site sanitation infrastructure. For this study, design-life sustainability is defined as infrastructure that is used and functions as intended throughout the asset design life. A total of fourteen experts, with both US domestic and international experience, were recruited from diverse fields such as academia, regulatory organizations, septic tank operations companies, and non-profit groups to review, add to, and comment on a list of factors generated from a content analysis of recent literature. The resulting data is a representation of the current state of the knowledge regarding factors that must be addressed in order to ensure design-life infrastructure sustainability for on-site treatment systems. Specifically, technology and economics, while necessary for system sustainability, must be complimented by knowledge, organizations, and motivational factors.

Traditional infrastructure asset management frameworks have focused on modeling the physical infrastructure asset. Infrastructure systems (IS) are a complex web of various physical and human elements that interact together to exhibit evolving behavior. This paper proposes the use of system dynamics (SD) modeling to represent the interactions that occur among physical infrastructure, system operators, infrastructure users and political decision makers. The proposed model considers; a) the assets' conditions, and deterioration rates, b) the operators' decisions and policies, c) the users' attitude and fees, d) the politicians' budget allocation decisions and political approval rates. Causal loop diagrams are developed to capture the relationships between these components and balancing / reinforcing loops are identified. An illustrative simulation example is presented to highlight how a change in the components of any of the four sectors under consideration, has a propagating effect through the other sectors. The developed SD simulation model can be used as a test bed to evaluate both short-term and long-term impacts of policy decisions on the goals of users, system operators and politicians.

Public Private Partnerships (PPPs) have emerged as an important project delivery method in the United States, where funding agencies are finding it difficult to support the increasing demand of highway projects. The United States has witnessed several types of PPPs during the past two decades, and a recent trend shows that newer designs of PPPs are being adopted for upcoming projects. Availability Payment, an extensively used PPP in the United Kingdom and Canada, is the newest performancebased PPP implemented in California and Florida. Extensive use of these PPPs in other countries strongly supports the belief of their widespread acceptance in the United States. The literature review indicates that concession term and availability payments are the most important parameters of this PPP. However, the public agencies do not have any solid tool that can design these parameters and have to largely depend on traditional methods. This research work introduces a hybrid model that will allow the public sector to determine the upper limit of availability payments and concession duration. The hybrid model has been developed by combining the stochastic dynamic programming model with multi-objective optimization principles. The model allows using private sector's financial condition, uncertainty of private sector's performance and the remaining life cycle costs of the asset. The use of this model ensures cost savings for the public sector and financial stability for the private sector simultaneously. This research includes an analysis of the CALTRANS' Presidio Parkway Project as a case study to demonstrate the use of the model.

According to the National Academy of Engineering, innovations such as intelligent transportation systems, alternative fuels, smart grids, and financial innovations are critical to enhancing the resilience and sustainability of infrastructure systems. The key to expansion of infrastructure innovations is effective policymaking. This paper adopts an Innovation System-of-Systems framework for policymakers to analyze innovation policies in interdependent infrastructure systems. The System-of-Systems framework facilitates consideration of the adaptive micro-behaviors of the components of the system within and across different levels of analysis. The application of the framework is demonstrated for the assessment of financial innovation policies for U.S. transportation infrastructure. Using hybrid Agent-based/System Dynamics techniques, a complex system model is created to simulate the micro-behaviors of state Departments of Transportation, private institutional investors, and the public. Different policy landscapes are developed using the output of the simulation model and classification and regression tree analysis as a meta-model. The quality of the model outcomes are evaluated through conceptual model validity, data validity, internal validity, and sensitivity analysis. The model provides policymakers with a tool to: (i) consider the effects of parameters in a complex system simultaneously and (ii) simulate the landscape of possible outcomes due to different policies.

Long term concession agreements as kind of Public-Private-Partnership (PPP) have been applied in infrastructure projects with equity participation by private sector. The concession approach to project financing has many advantages over traditional methods and as many concerns with nontraditional techniques. The growth of demand on financing infrastructure projects with public sector makes these projects deliver to the private sector throughout long term concession agreements. The main purpose of the right in long term concession is to cover infrastructure gap and reduce public concerns and protect the public interest and ,on the other hand, to encourage private initiative and benefit from the involvement of the private sector particularly in the designing, building, financing, operating and maintenance of infrastructure projects. We try to classify the most important criteria of long term concessions in the structure of matrix in four approaches: public objective, project properties, the project implementation and the environmental conditions. We show that various terms of contract can be investigated by considering these criteria in two infrastructure case studies of initial concessions in the United States.

The performance of subways is facing a lot of problems due to its age and lack of proper asset management planning. Many components in subways are deteriorating and their functionality is drawing back. Negative environmental impacts are uprising now which are represented in energy consumption and utilized materials in subways. There is a real need to develop a system that can measure the level of service and determine the key performance indicators. The system shall take into consideration prioritizing objectives to maintain certain level of service, the allocation of available budget and mitigation of negative environmental impacts. Before the emergence of the BIM technology, CAD files were used by facility managers to perform facility/asset management. However using CAD files in facility management had some problems like lack of information integrated within the CAD drawings, lack of coordination between different specialties and the complexity to interoperate other software. This paper proposes the application of BIM in subways by modeling different components including structural, mechanical, electrical, and HVAC. Each component is associated with its probabilistic deterioration model. The proposed system aids facility managers in rehabilitation decisions, taking in consideration priorities of objectives and budget allocation.

The limited financial capabilities of public owners gave rise to the Public-Private Partnership (PPP) approach as an innovative project finance to attract private investment to highway projects. Nonetheless, many privately financed road projects have had difficulties in fulfilling construction debt obligations due to operating deficits. These difficulties are mainly attributed to incomprehensive evaluation of project financial viability and poor selection of key concession items. This research presents a comprehensive framework which provides an optimal set of key concession items for setting up financial viable PPP toll road projects. These key concession items include toll rates, a concession length, an equity level, and a rate of return. The proposed framework utilizes a modified User Equilibrium traffic assignment algorithm to help estimate revenue from toll road traffic volume considering its interaction with levels of service. The framework also takes into consideration the relationships between the deterioration of the pavement serviceability and required maintenance caused by the traffic volume, which facilitates the quantification of the toll road maintenance expenditures. From the estimated cash flow, a Genetic Algorithm (GA) will be applied to search for an optimal combination of the key concession items that would maximize profit from private investment in public highway projects.

Close collaboration among stakeholders has long been recognized as an important factor of a successful project. In today's climate of a heightened focus on sustainability, collaboration needs to be taken to a new level in the design and construction processes. Most current project delivery systems can provoke adversarial relationships among involved parties. The objective of this research is to investigate the effects of project delivery system components on transportation projects performance. The research developed survey questionnaires and collected information on 84 projects, upon which multi-regression and step-wise regression analysis were performed. The research team then conducted a number of interviews to provide additional insight on important components of project delivery processes. The research findings identified high correlation between successful environmental outcome and the level of trades and suppliers expertise leveraged in early phases of the project and alignment of objectives among stakeholders. The analysis also shows that contractor's early involvement and information sharing among stakeholders are important factors for successful community related objectives. The research is expected to contribute to the knowledge of collaboration and project delivery systems in infrastructure construction by revealing the relationships between components of delivery systems and project performance.

The transportation agencies have historically focused on major building and expansion of roads, bridges, and other transportation infrastructure. However, the emphasis has drastically shifted from development of new infrastructure to intelligently maintaining the existing one. In recent years, budget tightening and increasing demands had also impacted the allocation of funds in transportation infrastructure. This situation has lead to emphasize the development of asset management systems. At its core, asset management is a business process that often changes the way of thinking in an organization and drives the decisions based on information. A strong asset management system provides a solid foundation that optimizes the performance and cost effectiveness of transportation facilities' operations and maintenance. Keeping in mind, this paper provides an overview of transportation infrastructure asset management. It provides a review of the best practices adopted by different transportation infrastructure agencies internationally & United States. The review shows that the front runners in the asset management system internationally are Australia while Michigan takes the lead in US. Finally, based on the review of best practices, a theoretical framework for transportation infrastructure asset management has been proposed. The framework is focused on six important aspects of an asset management system i.e. asset management organization and concept, planning, contractual arrangement and mechanisms, monitoring and performance measurement, information systems and decision making.

On March 28, 1979, the most significant nuclear reactor accident in US history occurred at the Three Mile Island Nuclear Power Plant. As a result, there have been no new nuclear power plants constructed in the US for over 30 years. Given the socio-political effects of this and other events in the history of commercial nuclear power, today the US industry faces an uncertain future. Consequentlythe US construction industry lacksnuclear construction experience and expertise in the use of advanced construction techniques necessary for successful delivery of nuclear construction projects. With the resurgence of nuclear power plants in the US, it is critical for US agenciesto develop a policy that willfoster and facilitate the development and utilization of advanced construction techniques in nuclear construction projects.Therefore, the objective of this research was toassess the current readiness of the nuclear construction industry, with respect to construction technologies. A questionnaire survey targeting experts from academia, industry, and government was conductedin order to investigate the current status of the US nuclear construction technologies. This paper presents an initial understanding of the current strengths and weaknesses of the US nuclear construction technologies intended to support US agencies in developingeffective policies regarding nuclear construction technologies.

Construction projects especially infrastructure projects are characterized by their uniqueness and individuality regarding their order specifics and location conditions. Considering the scope of services and service provision infrastructure projects imply a variety of special planning and construction features. The life cycle of infrastructure projects in Germany covers very long time periods from the conception to utilization. Depending on the scope and size of the project the planning and approval phase can take up to 12-20 years in Germany. This results not only from the fact that the planning and approval of infrastructure projects are associated with lengthy procedures but also because of the extensive stakeholder participation. For many decades the planning process of infrastructure projects has been unchanged in Germany and is characterized by high cost and time overruns. Further analysis with the aim of optimization seems to be appropriate and required. This paper reflects the current situation of the planning process of infrastructure projects with main focus on road construction projects based on a literature review and thereby resulting challenges in Germany. According to the results of a field study the paper also presents potential opportunities for optimization and further research.

Ultra-fine particles are increasingly being recognized as a potential threat to health. Aerosols in workplace environments may come from a wide variety of sources, depending on the type of activity and processes taking place. To quantify the level of risks associated with engineered nanomaterials, research needs to first quantify the level of nanoparticles' exposure encountered in different construction activities. Therefore, the objective of this study is to evaluate the potential inhalation exposure risk associated with Hot-Mix Asphalt (HMA) and concrete preparation activities in the laboratory. To achieve this objective, the number concentration, size distribution, surface area, and mass concentration were measured for different activities including dry mixing, wet mixing, pouring, and compaction in an asphalt and concrete laboratory using a Scanning Mobility Particle Sizer (SMPS). In addition, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) characterized the morphology, shape, and measure the primary size distribution of the particles. The estimates obtained by TEM analysis in the workplace study were similar to the estimates obtained by calculations using SMPS for the experimental study.

Marine environments include ions and corrosive gases and are the place of marine living things, which are destructive for construction materials. Hydrostatic pressures and high temperature changes, which are current in most of the coastal areas and marine structures, are able to accelerate decay of construction materials. Marine structures and port installations existing in ports are considered as important infrastructural installations that due to their concrete or metal nature are exposed to decay and destruction arising from being in marine environments. Concrete piles, which are executed in sea beds or in coasts, are affected by corrosive factors and the factors decreasing stability. Therefore methods and materials and special inspection system should be used to confront these factors. Undoubtedly Persian Gulf is one of the most corrosive and risky environments of the world for execution of concrete structures and concrete piles. This research tries to investigate the optimum methods for execution and maintenance and optimization of concrete piles and also concrete technology of these piles in Persian Gulf in details. In order to access this aim the geotechnical experiences of the piles and foundations executed in Persian Gulf and Omman Sea were used and finally some proposals for execution of such structures in destructive environments without any problem were offered.

Globally, many large pharmaceutical and biotechnology companies invest significant amounts of money to build manufacturing and laboratory facilities. One common concern amongst these companies is whether or not these facilities are efficient in their design and their use of human and financial resources. The Construction Industry Institute (CII) has worked with 12 of these pharmaceutical and biotechnology companies over the past seven years to benchmark the performance of their capital projects. In order to benchmark absolute cost performance (e.g., dollars per square foot), the projects' costs need to be normalized to account for location, time and currency. However, no single cost index is available to meet this need of normalizing global facilities. As a result, CII and the companies developed a procedure using established cost indices to reliably compare the cost performance of capital projects from different companies. This paper also discusses the issues and challenges of normalizing the costs associated with pharmaceutical and biotechnology capital projects. This paper contributes to a better understanding of cost normalization amongst global capital projects.

In the construction industry, previous research has shown that stable partnerships between contractors and subcontractors can evolve to an equilibrium point where transaction costs are minimized and profits for the involved parties are maximized. However, opportunistic behavior can lead toward a hold-up problem when there are incentives for continuous collaboration. In this case, one party attempts to capture more of the economic rents from continuous collaboration than the other party, which pushes the market beyond the equilibrium point to a less efficient state. To date this has been studied in the context of U.S. firm bidding interactions. Yet research has demonstrated significant differences in the behavior of firms in different market economies. In this paper we replicate an empirical bidding simulation conducted in the U.S. to examine opportunistic behavior and the evolution of market efficiency in China. We conducted 18 internet-based interactive bidding simulations through which we recruited 157 participants from China. Each participant submitted bids on up to 10 projects during each of the internet-based interactive bidding simulations. We collected information on each participant's bidding strategy and analyzed this information to understand how the market evolved with increasing experience. We then contrast the empirical findings from the U.S. experiment with the data we collected. The results demonstrate that opportunistic behavior can occur in China, but it differs from the U.S. in magnitude.

The problems of global warming and peak oil will cause us to reduce our dependence on fossil fuel and the automobile. There is compelling evidence that we will soon need to take action to reduce green house gas emissions and to conserve oil. The changes will require a shift to different modes of transport, particularly, rail for intercity freight and travel, and mass transit for transportation in urban areas. The construction industry must begin to prepare for an environment where there will be a decreasing emphasis on highway construction and more emphasis on the construction of high-speed rail alternatives.

Benchmarking is a systematic process of measuring an organization's performance against recognized leaders for the purpose of determining best practices that lead to superior performance. Benchmarking has been widely used by the private sector of the U.S. construction industry to improve their delivery of capital projects. While some studies have investigated the benchmarking of public transportation projects (e.g., highways and bridges), most of these focused solely on operations. This paper examines benchmarking efforts for public transportation projects delivery. Subsequently, this analysis is used to provide a framework of the opportunities and potential challenges inherent to benchmarking transportation projects delivery. This paper contributes to the foundational development of benchmarking standards for public transportation projects.

The Construction Industry Institute (CII) has developed 14 Best Practices to assist its membership with improving project and organizational performance. These Best Practices are widely used throughout the engineering and construction industries. Understanding that project needs and methods may differ widely across major industry sectors, four indicators have been developed as a way to measure how applicable CII research and practices are to four major industry sectors - Buildings, Infrastructure, Heavy Industrial and Light Industrial. An indicator of applicability was defined as a characteristic that can be used as a measure of how functional a Best Practice is to different industry sectors based on that characteristic. The concept was tested on the CII Best Practices to assess the extent of applicability to the four major industry sectors and project types. The main objective of this paper is to describe the research methodology and in particular the development of the applicability measures. These measures were used to assess applicability of 13 CII best practices following a three phase data collection approach. This research methodology proved useful in identifying gaps in applicability between the four industry sectors.

Using a case study analysis of Construction Industry Institute (CII) and Project Management Institute (PMI) member companies, this CII-funded research sought to understand the current use of risk management tools in the industry, including deterministic and probabilistic project-control techniques. The results indicate that formal risk analysis is not adopted universally. Given the benefits realized from the use of these tools, this research sought to understand why organizations are not using more formal probabilistic approaches to risk management. The research uncovered several barriers organizations face when trying to implement these probabilistic approaches, including a lack of organizational support, a lack of procedures, a lack of technical expertise to implement and interpret outputs, and a lack of transparency amongst stakeholders. By focusing on overcoming these barriers through training employees, adopting processes and procedures for risk management, and regularly communicating with project stakeholders; organizations can implement more formal project risk management approaches when warranted.

Effective front-end planning (FEP) has repeatedly been shown in past research to positively affect project outcomes. The results of poor FEP for a single project can potentially have a devastating and long-lasting effect on an individual organization. Since the economic world is becoming quite "flat" and extremely competitive, one question that can be asked is: why are there organizations with ineffective front-end planning strategies or none at all in this global economy? Members of the Construction Industry Institute (CII) were surveyed to identify barriers to effective front-end project planning, with 59 organizations responding. Common barriers such as lack of adequate resources will be discussed in this paper. Over 70 percent of respondents use at least one CII-developed FEP tool in their planning process and the use of tools has had a positive effect in overcoming barriers to effective planning. This paper will describe survey results and give recommendations to practitioners for improving FEP efficacy in order to improve capital project portfolio.

A primary purpose of this on-going research sponsored by the Construction Industry Institute (CII) is to develop a strategic set of industry practices for estimation, control and management of indirect construction costs (IDCC) at the project level. Researchers conducted structured interviews with 56 subject matter experts to investigate and map widely adopted and novel practices, specifically addressing certain "key" groups of IDCC. The rich findings from these interviews have been aggregated into an instructional guidebook which includes empirical consideration checklists, comprehensive process flowcharts and practical tools. Eighty-nine percent of interviewees reported that project success can be improved through better handling of IDCC. This research seeks to fill this performance gap by enabling owners and contractor to easily adopt the recommended practices into standard operating procedures. To establish a shared vocabulary for IDCC, this paper summarizes literature pertaining to IDCC and proposes a two-part operational definition comprised of a lexical definition and a categorization framework. The findings are outlined from a contractor's perspective and focus on costs most commonly incurred by construction companies at the project level. This paper presents a partial consideration checklist and a process flowchart for major construction equipment. Lastly, this paper describes the on-going validation methodology.

Concrete activities are typically critical to a project's schedule, therefore examining how to improve their labor productivity can have a direct impact on a project's overall performance. As part of a research program to improve construction productivity sponsored by the Construction Industry Institute (CII), the authors investigated innovations in the concrete trades and their impact on labor productivity. The innovations studied were 100ksi steel reinforcement, self-consolidating concrete (SCC), and modular formwork. The 100ksi reinforcing steel study analyzed a typical beam cross-section and compared its total weight to that of a typical 60ksi reinforcing design. Often, high strength reinforcing steel is a lower cost alternative to a standard design due to lower amounts of steel. The SCC study collected quantities and unit rates of SCC and a comparable conventional mix at several projects. The projects using SCC had faster placement unit rates compared to conventional concrete mixes. Modular formwork was found to have significant advantages in productivity over stick-built formwork systems. From the analysis of a sample project, modular formwork gains a cost advantage at varying floors based on local labor rates. The findings should help management understand performance of these concrete innovations when considering their use.

Jobsite management functions and associated staffing levels among both Owners and Contractors have increased in number and complexity in response to the demands for greater levels of jobsite management. However, there is little published guidance or clarity on jobsite organization metrics or approaches. The primary purpose of this research was to identify and describe industry norms pertaining to jobsite Owner and Contractor organizational functions and staffing levels. This is the first jobsite organization benchmarking study of its kind. Benchmark metrics derived from this research pertain to Owner and Contractor jobsite organization size and constituent roles. Organization size has been reported and analyzed in terms of both staff full-time equivalent (FTE) and craft-to-staff ratio (CSR). For the sample of projects examined, jobsite organization team size and CSR metrics vary significantly under certain project characteristics. Norms regarding FTE and CSR metrics and the knowledge behind such information are reported in this paper. Also, the sampled projects suggest that there are six jobsite organization core roles for Owners and 16 such roles for Contractors, which are essential to jobsite team staffing. It's evidential from the results that most project managers participating this research would do differently, by adapting the new information generated by new logic and metrics, to improve project performance.

Front end planning (FEP) is recognized by both academia and industry for its potential for improving project success. Despite wide acceptance of its value, the FEP process varies in its implementation throughout the construction industry and from one project to another. Diverse circumstances will require different human and financial resources for successful implementation. The Construction Industry Institute (CII) has captured the FEP implementation efforts of leading owners and contractors since 1996 through CII's Benchmarking and Metrics (BM&M) program. This paper quantifies several parameters for successful FEP implementation effort in terms of cost, schedule and project management (PM) team size. The paper also examines selected parameters in light of several project characteristics. Analyses show that FEP implementation efforts differ depending on project characteristics such as industry type and project nature, amongst others. The quantitative summaries presented in this paper will help practitioners plan for appropriate levels of implementation and resource utilization during front end planning.

Masonry construction is one of the specialty trades with high risk of workrelated injuries. This case study analyzes 141 masonry incidents that occurred over a period of three years in a large masonry company. Incident analysis and interviews with the safety director and production managers identified the masonry tasks with high frequency and severity of incidents, the task factors that contribute to incidents and the events that resulted in incidents and injuries. Furthermore, the study categorizes the incidents according to the injured workers' position such as foreman, masons, laborers, and forklift operators. The findings indicate that three activities—scaffold erection and dismantling, laying block and material handling are responsible for the highest number of incidents and consequences in terms of days away from work and days with modified task. The second finding in this case is that laborers of masonry crews have disproportionately more accidents compared to the masons. The study makes the following contributions to practice: first, it identifies the high-risk activities of masonry operations that require more effective controls to improve workers' safety, and second it distinguishes between the traumatic injuries of laborers and masons, and identifies the population with higher injury risk.

Increasing globalization is creating both challenges and opportunities for engineering and construction companies. Many researchers have examined the drivers and key success factors for globalizing engineering and construction firms to become truly global. Comparatively little research has focused on how engineering and construction firms integrate their globally dispersed business activities as they globalize. This paper presents the research efforts of a Construction Industry Institute (CII) research team that developed a model by which firms can assess their globalizing performance in two dimensions; global reach and global integration. We developed an excel based electronic survey and tool called the Globalizing Self-Assessment Tool (G-SAT) which enables the calculation of a two-dimensional globalizing performance score for engineering and construction firms. We collected data from 36 companies to validate the benchmarking functionality of the G-SAT. In order to further validate the ability of the G-SAT to track globalizing performance across business periods, we also collected and plotted the 15 year globalizing history in 5 year increments for eight companies. This research contributes an index and associated tool to measure engineering and construction firms' globalizing performance.