Journal of Construction Engineering and Management

This paper presents the development of advanced labor demand forecasting models at project level. A total of 11 manpower demand forecasting models were developed for the total project labor and ten essential trades. Data were collected from a sample of 54 construction projects. These data were analyzed through a series of multiple linear regression analyses that help establish the estimation models. The results indicate that project labor demand depends not only on a single factor, but a cluster of variables related to the project characteristics, including construction cost, project complexity attributes, physical site condition, and project type. The derived regression models were tested and validated using four out-of-sample projects and various diagnostic tests. It is concluded that the models are robust and reliable, which merit for contractors and HKSAR government to predict the labor required for a new construction project and facilitate human resources planning and budgeting, and that the methodology used may be applied to develop equally useful models in other subsectors, and in other countries.

A problem that always annoys building employers and their consultants when drafting building contracts is whether it is more cost efficient to retain certain risks with themselves or to transfer the same to contractors, and it has long been a difficulty to accurately estimate the cost for transferring risks to the other contract party. It is a very common market practice to remove contractors’ entitlement to extension of time due to inclement weather, and in view of the significant impacts that inclement weather posed on construction progress, it would be helpful to assess the associated costs for such risk allocation exercises in order to ensure that it is a cost-effective transaction. The costs for these potential weather-caused delays are priced by contractors in their returned tenders. This risk-pricing behavior is affected by the contractor’s risk perception and risk attitude. However, merely working out contractors’ risk perception and risk attitude patterns is inadequate, as they may vary in accordance with different organizational sizes and project backgrounds. Therefore, further studies should be carried out on the implications of project information, such as project value and contract period, on different-sized contractors’ risk behaviors. In this research, a questionnaire survey was conducted to investigate the weather-risk-pricing behavioral patterns of various-sized contractors under different given project scenarios. The survey revealed that the impacts of project value and contract period (and, thus, the intensity of work and scale of exposure to weather risk) were significant on contractors’ risk behaviors, and these impacts varied in accordance with different organizational sizes. The medium-sized contractors’ pricing behaviors were rather constant under different project values and contract periods, while both small and large contractors behaved differently when the intensity of work and scale of risk exposure varied. Despite the fact that contractors of various sizes behaved differently in some given scenarios, the number of days of delaying cost allowed by them in returned tenders were generally less than the actual number of days of inclement weather affecting work.

Cooperation is fundamental to successful procurement and delivery of building and civil engineering projects. This study explores the role of perceived fairness as a motivator of cooperative behavior in the process for administering project claims. The objective is to investigate how a contractor’s perceptions about fairness of the procedure for administering project claims would interact with the outcome received from the claims to influence the contractor’s cooperative behavior in terms of conflict intensity and potential to dispute. The data collection instrument was a structured questionnaire. Face-to-face interviews were conducted with 41 contractors’ personnel regarding their experience with claims on 41 completed projects in Singapore. The data were analyzed using the structural modeling approach. The results indicate that on projects where contractors did not receive a favorable outcome from claims, there was lower intensity of conflict and lower potential to dispute when contractors perceived that the procedure for administering the claims was fair than when the procedure was perceived to be unfair. The findings suggest that, in construction, cooperative behavior is a combined function of the outcome and procedure leading to that outcome. It also suggests that enhancing cooperative behavior goes beyond formal contract provisions but rather how the contract is administered in practice. It is recommended that employers’ project management team whose actions of rejecting invalid claims may be misinterpreted and disputed pay greater attention to how decisions on claims are reached. A fair procedure could cushion the effect of an unfavorable decision and thereby reduce a contractor’s uncooperative attitude.

Delayed completion of a construction project is often caused by a complex interaction of a combination of events, some of which are the contractor’s risks and others are the project owner’s. The apportionment of the liability to give effect to the risk allocation has therefore been a matter of great controversy. Many delay analysis methodologies have been developed over the years for performing this task. This paper reports on an empirical study into the current practice in the use of these methodologies in the United Kingdom, as part of a wider study aimed at developing a framework for improving delay claims analysis. The part of the study reported here was based on a questionnaire survey of key informants. The issues investigated include the categories of staff within contracting organizations who contribute to delay claims analyses, the awareness, use and reliability of existing delay analysis methods and the obstacles to their use in practice. The main findings of the study are that: (1) the preparation of delay claims often requires input from commercial managers (quantity surveyors), schedulers, site managers, external claim consultants and estimators; (2) commercial managers have the greatest involvement; (3) claims analyzed using the as-built versus as-planned and the impacted as-planned techniques are often successful although there is considerable literature on the shortcomings of these techniques; and (4) the main obstacles to the use of the methods relates to deficiencies in project records and scheduling practice.

A significant number of large-scale civil infrastructure projects experience cost overruns and schedule delays. To minimize these disastrous consequences, management actions need to be carefully examined at both the strategic and operational levels, as their effectiveness is mainly dependent on how well strategic perspectives and operational details of a project are balanced. However, current construction project management approaches have treated the strategic and operational issues separately, and consequently introduced a potential conflict between strategic and operational analyses. To address this issue, a hybrid simulation model is presented in this paper. This hybrid model combines system dynamics and discrete event simulation which have mainly been utilized to analyze the strategic and operational issues in isolation, respectively. As an application example, a nontypical repetitive earthmoving process is selected and simulated. The simulation results demonstrate that a systematic integration of strategic perspective and operational details is helpful to enhance the process performance by enabling construction managers to identify potential process improvement areas that traditional approaches may miss. Based on the simulation results, it is concluded that the proposed hybrid simulation model has great potential to support both the strategic and operational aspects of construction project management and to ultimately help increase project performance.

The analysis of project schedules is among the central tasks of construction managers. Parallel to the well-known critical path method, linear scheduling techniques have been researched. The two most fully developed existing methods, the linear scheduling model and the repetitive scheduling method, are reviewed. Based on a discussion of a published example, the new mathematical analysis method for linear and repetitive schedules is introduced. The productivity scheduling method is based on singularity functions that provide a flexible and powerful mathematical model for construction activities and their buffers that are characterized by their linear or repetitive nature. The steps of formulating initial equations, stacking and consolidating them, and deriving information about their criticality are described in detail. The mathematical approach of the new method allows an integrated treatment of activities regardless of the number of changes in productivity within them and does not depend on the graphical representation of the schedule.

Time and cost are the most important factors to be considered in every construction project. In order to maximize the return, both the client and contractor would strive to optimize the project duration and cost concurrently. Over the years, many research studies have been conducted to model the time–cost relationships, and the modeling techniques range from the heuristic methods and mathematical approaches to genetic algorithms. Despite that, previous studies often assumed the time being constant leaving the analyses based purely on a single objective—cost. Acknowledging the significance of time–cost optimization, an evolutionary-based optimization algorithm known as ant colony optimization is applied to solve the multiobjective time–cost optimization problems. In this paper, the basic mechanism of the proposed model is unveiled. Having developed a program in the Visual Basic platform, tests are conducted to compare the performance of the proposed model against other analytical methods previously used for time–cost modeling. The results show that the ant colony system approach is able to generate better solutions without utilizing much computational resources which provides a useful means to support planners and managers in making better time–cost decisions efficiently.

The American Society of Civil Engineers claims that corruption accounts for an estimated $340 billion of worldwide construction costs each year. Corruption (including bribery, embezzlement, kickbacks, and fraud) in construction projects undermines the delivery of infrastructure services. Further, corruption poses significant risks to construction and engineering companies themselves. What progress has been made, therefore, in reducing the risk of corruption to construction projects? It is the purpose of this paper to argue that with improved accountability, attention to ethics and cultural considerations, and reduced corruption, it is possible to construct, operate, and maintain adequate quality and quantity of infrastructure on a more sustainable basis and thereby improve construction practice. This paper will demonstrate how accountability initiatives in construction projects in developed and developing countries can be of benefit internationally to the public and private sectors as well as nongovernment organizations and researchers in their efforts to reduce corruption in infrastructure services.

Layout of temporary facilities on a construction site is essential to enhancing productivity and safety, and is a complex issue due to the unique nature of construction. This paper proposes a particle swarm optimization (PSO)-based methodology to solve the construction site unequal-area facility layout problem. A priority-based particle representation of the candidate solutions to the layout problem is proposed. The particle-represented solution in terms of priorities should be transformed to the specific layout plan with consideration of nonoverlap and geometric constraints. In addition, a modified solution space boundary handling approach is proposed for controlling particle updating with regard to the priority value range. Computational experiments are carried out to justify the efficiency of the proposed method and investigate its underlying performances. This study aims at providing an alternative and effective means for solving the construction site unequal-area layout problem by utilizing the PSO algorithm.