Journal of Construction Engineering and Management

Constructors and civil engineers have made significant contributions to the quality of life everywhere. Their role has changed from that of scientists and project managers to coowners and financiers. The next incremental and perhaps final change has to be that of making policy and not carrying out directives by others. This evolving role must lead the constructor engineer to become a part of the decision-making bodies to chose the project rather than execute them only. Constructors and engineers designed well-planned cities of yore, that people love to tour and visit, well before the advent of planners. In the future they will have to do so again. Urban sprawl as presently planned is just not feasible. This paper discusses the role of the constructor/engineer in the next 25 years, toward the year 2020, and argues for a change in the passive role of the constructor/engineer as an educator, innovator, policymaker, and decision maker to an active one in charting societal changes driving into the beginning of the next millennium.

This paper is concerned with one of the most important tasks in construction management—scheduling of construction project—and shows how to optimize the overall construction schedule. The current optimization methods seem to provide very little support for construction project managers, as the managers require a schedule based on the simultaneous considerations of several factors, such as investment allocation, total cost, resource supply, and weather. With a view of systematization, the paper first quantitatively analyzes the factors that influence the overall construction schedule. It then indicates that the optimization of overall construction schedule must be closely combined with the investment allocation, resource supply, and weather. The relationships between these factors are analyzed, and their mathematical submodels are established. Based on these submodels, a mathematical model is then established with the objective of the best economic benefit (the lowest construction cost). Finally, the solution of this model is provided, a computer program is developed to solve this model, and an example is taken to show the procedures of solution.

Expert knowledge and lessons learned in the construction phase of a project are not systematically incorporated into the design and construction phases of subsequent projects. The advancement of construction since ancient times has been predicated on the communication of lessons learned. Although past efforts have focused on the design phase, opportunities for the collection and utilization of lessons learned exist in all phases of a project life cycle. Constructability, the early integration of construction knowledge into all phases of a project, can be improved by effective use of lessons learned. This paper identifies feedback channels in a project life cycle and describes previous and current efforts to develop lessons-learned systems. Next, the paper describes the design and implementation of a constructability feedback prototype called interactive knowledge-intensive system (IKIS) for constructability improvement (IKIS-Constructability). Finally, the paper highlights the operation of this system and its potential benefits.

The importance of cash-flow management, and thus the need for it, is a matter of consensus among researchers and practitioners alike. They all agree about the difficulties in generating automatic cash-flow forecasts at the project level due to such problems as compatability—which is explained in this paper—or the lack of detailed data. At the company level it is even more difficult to forecast cash flow, due to the varying levels of data detail for different projects. The paper begins with a comprehensive background of cash-flow management. It then describes the development of a cash-flow management model for the organizational level, followed by the detailed computer program written on this basis. The system presented here is unique because it manages the cash flow of the company as a whole, it is flexible—accepting projects with varying degrees of detailing levels, it requires no human involvement in cash-flow generation, it is accurate, and it is a typical management tool. The uses of such a tool are also discussed.

This paper presents an updated and enhanced version of a study conducted by the task force of the Construction Owners Association of Alberta (COAA) on “More-Stable Contractor Relationships.” The purpose of the study was to explore the current contracting philosophies, strategies, methods of execution, tendering processes, and techniques. The purpose of the study was also to identify the problem areas and determinants of success in the execution of projects, and to share these findings with the industry for further improvement. We have found that the industry is somewhat complacent and appears reluctant to embrace change. There is a preoccupation with contract award on the basis of lowest lump-sum bid although most recognize that this often results in a higher end price for the product. There is a need for improvement in the areas of life-cycle costing, contracting process, risk management, teamwork, trust, and cooperation, as well as communication and the use of quality management principles. There are ample opportunities to be more progressive. The survey and subsequent evaluation concluded that any initiatives to formulate more stable contractor relationships must come from construction owners.

Constructibility, in simple words, is the ability to construct effectively. This study involved the development of a prototype system to perform highway constructibility analysis of traffic-control planning (TCP). The results of meetings with personnel at the Texas Department of Transportation (TxDOT) indicated that work-zone traffic control is one of the most critical factors impeding the constructibility of highway projects. The lack of personnel, the inability to fill the knowledge void caused by transfer or retirement of experts in the field, and the inability to effectively learn from mistakes are some factors that indicate a need for advanced automation techniques in the highway construction industry. The prototype system developed included a database module (CONTRAF), an expert system module (TRAPS), and a fuzzy scheduling module. It is developed to provide designers and construction managers with generic constructibility recommendations on traffic control, and direct access to a constructibility database, before the final TCP is designed. Once the final TCP is developed, the system helps in phasing the activities, calculating the fuzzy durations of the activities, and linking the activities to a project-management software for project scheduling.

Because of the constraints of the existing building, a reconstruction project is more complicated and difficult than a new project, and a multiphase reconstruction project is even more complicated and difficult than a single-phase reconstruction project because of the additional constraints imposed by the owner to ensure the normal operation of the remaining portion of the building. In this study, the experiences gained during the first five phases of the multiphase reconstruction of the Technological Institute building on the Northwestern University campus in Evanston, Illinois, are examined through a review of the construction documents and interviews with representatives of virtually all the major parties involved in the project. The problems encountered are then analyzed within the framework of the contractual approach used and the experiences accumulated, primarily from the construction of new facilities, to deduce the variety of lessons learned. Chief among these lessons are: (1) The strong need for effective project management at all levels with continuous communication among all parties and the authority to render timely decisions; (2) the importance of a contract document that establishes a strong basis for handling uncertainties and changes that arise during construction; and (3) the special problems that stem from the multiphase reconstruction of a combined academic and research facility.

A significant part of waste generation is caused by the building and construction industry. Reduction of construction waste is therefore a major topic of the integrated chain management policy of the Dutch government. Construction companies benefit from reduced waste generation by lower deposition costs and lower purchasing costs of virgin materials. An overview is presented of the main policy areas of the Dutch government concerning sustainability. Reducing the generation of construction waste fits into this policy. Subsequently, an overview is presented from construction-waste data available in literature. Then, the waste generation during several Dutch residential construction projects has been quantified and analyzed in detail. It follows that about 1–10% by weight of the purchased construction materials, depending on the material, leave the site as waste. Furthermore, the analyses identify additional sources of waste generation as those already known, such as a lack of attention paid to the sizes of the used products, lack of influence of contractors, and lack of knowledge about construction during design activities.

This paper provides strategies for improving construction safety performance through the analysis of numerical profiles of companies and projects with varying levels of safety performance. This research perspective compliments much of the previous safety-related research, which tends to be more qualitative in nature, addressing “what” factors are important for success as opposed to “how much” is appropriate to achieve successful safety outcomes. Corporate safety coordinators completed questionnaires that solicited quantitative data (e.g., number of safety inspections, dollars spent on safety program, and percentage of time devoted to safety issues) at both the company and project levels. Several safety performance measures were investigated: Occupational Safety and Health Administration (OSHA) incidence rates, experience modification rating (EMR), and a subjective project performance rating. Forty eight company programs and 69 individual project safety programs are included in the analysis. Results from the statistical data analysis point to several company- and project-specific factors that are statistically significant in improving safety performance. This paper can benefit contractors, specialty contractors, and owners by providing them with objective strategies to consistently achieve better safety performance.

The decline in government funds and the increased demand on public agencies for the construction of new (or the rehabilitation of existing) infrastructure projects has led to the growth of alternative forms of project development, such as BOT and BOO. The Desirability Model, presented in this paper, is a multiattribute evaluation model that provides a logical, reliable, and consistent procedure for assessing the capability of a private-sector company to become a promoter for a given project and the attractiveness of an infrastructure project to be actively promoted by a given company. The proposed model was developed with the assistance of 14 experts from around the world. It produces two indices (one for company competencies and one for project attractiveness) that depend on the actual performance levels of a total of 23 company and project attributes. The model has been validated by comparing these indices to the experts' holistic evaluations of 19 company and project profiles. Example applications of the model include the evaluation of the Eurotunnel and an illustration of how sensitivity analysis can identify strategies for project improvement.

The heart of the competitiveness in the U.S. construction industry has always been the skilled workforce that has been available to implement the technology of construction. During the late 1980s, many experts predicted severe shortages in the skilled workforce by the year 2000. This perception was based on demographic shifts in our population and the demands for workers in other areas of the economy. Based on this perception, a study was undertaken to examine the issues and survey a broad cross section of the craft workforce. This paper describes the results of a questionnaire administered to more than 4,600 craftworkers throughout the United States concerning their perceptions of their job, career, and employment conditions. The results of this questionnaire provide new insight into how craftworkers perceive job satisfaction, satisfaction with the financial aspects of construction work, career orientation, and pride. The study provides a model for individual companies to develop similar surveys to assess their employee's perceptions. The survey provided an opportunity to gather a broad range of information regarding the perceptions of our current craft workforce. The insights provided by this survey should provide a basis to address problems that may arise with craftworker shortages in the United States. A better knowledge of the perceptions of the craft workforce results in the potential to improve the management's ability to get the best out of the construction workforce, retain skills that currently exist, and build a strong and competitive future workforce.

Serious injuries and costly damages caused by excavators hitting underground utilities are constantly in the headlines of the news media. The accidents sometimes result in the death of one or more persons. Thus, excavation represents a dangerous operation that has to be executed with care. The Construction Automation and Robotics Laboratory at North Carolina State University has been searching for a technology to help avoid these types of accidents. A prototype of the active metal detection and tracking system has been developed using a nontraditional approach. The system generates and transmits its own magnetic impact and detects the coupling effect with any buried utility line in its detection range. It is installed directly on the excavating equipment and integrated with its operation. Experiments have been carried out with this system and the results are promising. The work deliberated in this paper presents an ongoing effort to develop an effective and reliable system that can be attached to any type of construction and utility digging equipment for underground utility line detection.

Employers of construction workers have become increasingly concerned about worker safety in the past decade. Although the Occupational Safety and Health Administration (OSHA) regulations provide safety guidelines, they do not indicate the relative importance of the different paragraphs. While a common-sense approach might help these employers to focus on the appropriate work conditions, additional help might be gained from an examination of data that identifies specific paragraphs of particular interest. These paragraphs are associated with the greater number of violations. Paragraphs of even greater interest might be those in which a high proportion of violations are of a serious nature. Research shows that the paragraphs involved in the most violations are not necessarily those involved with the same relative number of serious violations. Although no claim can be made that these paragraphs identify the areas where most workers are injured, they do identify areas that warrant particular attention by employers.