Journal of Construction Engineering and Management

It is widely accepted in the construction industry that contract documents, specifying the responsibility and risk of each participant, are the basis for project managers’ and superintendents’ decision making (DM). However, in practice strict adherence to the formal procedures and chains of command would not always be possible without an unacceptable expenditure of time and money. Although much attention is given to the decisions at the project manager and superintendent level, the underlying rules and mechanisms for the moment-to-moment DM at the site management level has not been documented. In this paper, a social network (SN)–based data envelopment analysis (DEA) benchmarking procedure (SDBP), which combines DEA (assessing the relative efficiency of DM units) and SN (concentrating on the relationships amongst DM units) to identify the benchmarks for the inefficient specialty trades (STs). This paper also uses a case study to illustrate how to implement the SDBP. This research contributes to the body of knowledge because it combines the DEA and SN analysis for the first time to propose a new method of identifying the improvement direction (benchmarks) for STs of a project. This technique is beneficial to project managers because it (1) untangles the role and effectiveness of the existing interactions and interdependencies among the STs, (2) evaluates the STs’ potential for being benchmarks, and (3) outlines how an inefficient ST can improve its performance through learning from the practices of other good performers (social learning).

Social and political dynamics increasingly determine the fate of infrastructure development around the world. Decision makers involved with projects such as the Keystone XL pipeline in North America, the Belo Monte Dam in Brazil, and the Bujagali Dam in Uganda have been forced to substantially change their plans as a result of opposition. This study looks at such emergent dynamics to provide a quantitative assessment of risks associated with social sustainability in infrastructure development. An interactional model is proposed to analyze emergent risks in a complex system of systems and it is applied to emergent risks in infrastructure development. The analysis is based on the game-theoretic equilibria for an interaction between two actors, namely, the developer and the opposition. Using simulation the structural and contextual variations were investigated in the context of the project along with consequent emergent patterns of outcomes and associated risk profiles. The model comprises informal and formal interactional stages to investigate the impact of alternative mitigation strategies on project risk. The application of the proposed methodology is showcased in an analysis of informal and formal strategies to deliver socially sustainable projects.

The employment of nontraditional materials such as soil-rock mixtures, for economic and environmental reasons, in the construction of earthworks poses some new challenges for compaction techniques and their control, and for the determination of the embankment characteristics that result from the compaction method. Those characteristics experience important changes according to the relative percentages of the existing fractions. Usually, this kind of material results from bulky rock extraction without explosives, and it can include some large-size particles (greater than 0.5 m). In addition, the measured deformations associated with these materials have been larger than expected. For the execution control of the soil-rock mixtures from the Odelouca dam borrow areas, a series of vibratory and standard compaction tests was performed to estimate reference values for the maximum dry density and optimum water content of these materials, and a new methodology was proposed. The Odelouca dam is a zoned embankment dam, 76-m high, with clayey soil in the core and weathered schist with a significant fraction of oversized particles in the shells. This paper presents the results of the compaction control in addition to the dam performance during the construction and first filling phases as a validation of implemented construction procedures.

The requirements for edge protection systems on most sloped work surfaces (class C, according to EN 13374-2013 code) in construction works are studied in this paper. Maximum deceleration suffered by a falling body and maximum deflection of the protection system were analyzed through finite-element models and confirmed through full-scale experiments. The aim of this work is to determine which value for deflection system entails a safe deceleration for the human body. This value is compared with the requirements given by the current version of EN 13374-2013. An additional series of experiments were done to determine the acceleration linked to minimum deflection required by code (200 mm) during the retention process. According to the obtained results, a modification of this value is recommended. Additionally, a simple design formula for this falling protection system is proposed as a quick tool for the initial steps of design.

The lack of the expertise and resources, the unavailability of sufficient and complete operations data, and the absence of relevant site information present obstacles to applying combined simulation modeling in practice. Construction modelers are required to make critical decisions in a short turnaround time for planning operations and improving productivity. Thus, a more convenient discrete event simulation-based approach in simulating the production capacity of the continuous plant given limited data availability is desirable and formalized, which essentially discretizes the modeling of continuous elements in a predominantly discrete system without loss of significance or accuracy. As such, a direct application of a discrete simulation method intended for construction applications will offer a straightforward, sufficient solution to model the whole system. A concrete pumping case is used to illustrate the proposed approach. The effectiveness of the proposed approach is further demonstrated to tackle a real-world challenge: modeling iron ore mining operations to achieve efficiency and enhance productivity. Especially, the formula proposed is applied to simplify the modeling of the iron ore processing plant with magnetic separation drums, which constitutes the major plant used for extracting iron sand from the slurry of iron ore. A discrete event simulation model was rapidly developed for the complex mining system and the insight derived from simulation experiments assisted a mining company in (1) configuring the processes of raw sand excavation, iron sand magnetic separation and iron sand shipment at a seaport, (2) optimizing resource allocation and utilization. In conclusion, the proposed approach adds to the usefulness and flexibility of a discrete simulation methodology in modeling complicated construction systems.

This paper presents the definition and the mathematical formulation of a unique performance metric called the project quarterback rating (PQR). The PQR gives a specific score for each construction project based on a set of key variables affecting project performance and outcome. The importance of the PQR is found in its ability to quantitatively assess overall performance from the contractor’s perspective, taking into account key performance areas, which include customer satisfaction, schedule, cost, profit, and communication. A practical application comparing the performance of several recently completed projects is also presented in this paper to illustrate the new model. This application shows one of many possibilities for how PQR can be used to solve industry problems and to fill an existing gap in the literature. This research offers a contribution to the construction engineering and management literature and to the architecture/engineering/construction (AEC) industry. It is the creation of a unified project performance metric for a practical comparison of overall performance for any construction project.

When estimating the duration of the construction stage during the design stages of construction projects, empirical models are often used as a substitute for more accurate estimates based on detailed scheduling. These models, traditionally designated as time-cost relationships (TCR), derive from regressions relating the duration of concluded construction projects with characteristics that can be easily foreseen during the planning and design stages—both quantitative (e.g., cost, gross floor area, number of floors) and qualitative (e.g., type of contract). This paper reviews the approaches that have been adopted to develop the TCR models and discusses the complementary roles that statistics and engineering judgment can play towards their optimization and enhanced accuracy. This discussion includes the statistical and practical implications of (1) the quantitative independent variables used, (2) the qualitative independent variables used, and (3) the mathematical structure used. The paper aims at demonstrating the importance of sound statistics and highlights some of the most common mistakes. Additionally, it provides illustrative examples to show the complementary role that engineering judgment should have in the process of developing more robust, reliable, and accurate statistical-based TCR.

In spite of advances in formalizing space-use analysis (SUA) methods, which predict space utilization of buildings based on user activities and spaces, a detailed ontology that provides architects with a common vocabulary to represent their information about user activities is still lacking. The authors created an ontology that can be used in a formalized SUA method by extending combined existing theories on representing user or construction activities. This ontology allows architects to represent a user activity in a <User>, an <Action>, and two <Spatial requirement> instances. It also allows a computer to distinguish between 288 different space-use types that affect SUA and treat them differently. This paper contributes to the field of performance-based building design by offering a means of expressing user activities in a computer-interpretable form and using them in SUA, which informs about space utilization (a performance criterion) of a design option.

The design/build (DB) system is regarded as an effective means of delivering sustainable buildings. Specifying clear sustainability requirements to potential contractors is of great importance to project success. This research investigates the current state-of-the-practice for the definition of sustainability requirements within the public sectors of the U.S. construction market using a robust content analysis of 49 DB requests for proposals (RFPs). The results reveal that owners predominantly communicate their desired level of sustainability through the leadership in energy and environmental design (LEED) certification system. The sustainability requirement has become an important dimension for the best-value evaluation of DB contractors with specific importance weightings of up to 25%. Additionally, owners of larger projects and who provide less design information in their RFPs generally allocate significantly higher importance weightings to sustainability requirements. The primary knowledge contribution of this study to the construction industry is the reveal of current trends in DB procurement for green projects. The findings also provide owners, architects, engineers, and constructors with an effective means of communicating sustainability objectives in solicitation documents.

Enterprise risk management (ERM), as a holistic approach to risk management, has been advocated in the construction industry. The objectives of this paper are to assess the ERM maturity in Chinese construction firms (CCFs) based in Singapore and uncover how ERM was implemented in these firms. Through a questionnaire survey with 35 CCFs, the data relating to ERM implementation were collected. The analysis results indicated a low level of ERM maturity in these firms, and the positive association between ERM maturity and firm size. In addition, risk communication, objective setting, and risk-aware culture were the top three scores, while formalized key risk indicators and a risk management information system were the bottom two scores. Moreover, three case studies were conducted. The cross-case comparison results substantiated the survey findings, highlighted the influence of the parent firms on the ERM implementation, and indicated that the firms without formal ERM implementation can still have some practices consistent with the ERM fundamentals. These empirical results are arguably the first to be presented for the construction industry and therefore add to existing knowledge of ERM. In addition, various organizational issues have been identified that may influence ERM maturity. The future development of the ERM body of knowledge can, for enhancement purposes, take into account ERM maturity as well as the organizational issues for implementation. Furthermore, the ERM maturity of Singapore-based CCFs can serve as a ballpark benchmark, with which the other firms can compare in terms of ERM practices, and the similar research design and method can be used to investigate ERM implementation in CCFs located in other countries. Therefore, this paper significantly contributes to the ERM body of knowledge.

Many state departments of transportation are currently shifting more acceptance sampling and testing responsibilities to contractors because of a shortage of personnel at highway agencies and intensive construction schedules. The practice of using contractor-performed test results for acceptance decisions is referred to here as contractor acceptance testing (CAT). Studies have shown the need for improving the power of the statistical process used to validate the contractor’s test results. A potential improvement to CAT is to accumulate contractor’s and agency’s test results of consecutive lots to increase sample size and consequently increase the power of the statistical tests used to verify the contractor’s test results. In this study, two different types of cumulative sampling methods (i.e., continuous cumulative and chain lot) are applied to actual test results obtained from the Kansas Department of Transportation (KDOT), which includes contractor-performed test results and agency-performed test results from independent samples. The percent within limits (PWL) calculated according to KDOT’s acceptance practices was compared to the PWL obtained by the alternative methods for more than 90 projects. The results show that a chain-lot method with three accumulated lots is a plausible way to increase the power of the F-test and t-test. The contribution of this study is a practical sampling method for state DOTs to improve their CAT practices by increasing the power of the F-test and t-test used in the verification process while staying close to current agency’s practice in terms of pay factors.