Journal of Construction Engineering and Management

Assessing time contingency is an important part of construction project scheduling because it helps generate a more reliable schedule. Traditionally, the assessment is made using expert judgment and inherently inserted to the estimated activity duration and/or comprehensively placed at the project level. This practice has a major drawback in that project-specific risks that require time contingency are not explicitly identified and treated. Risk management is performed in isolation to project scheduling. This paper presents a new framework for assessing the time contingency required for activities exposed to multiple risks. Fuzzy set theory is employed to model the imprecision and vagueness associated with the possibility of risk occurrence and the impact of those risks on activity durations. Alternative risk responses can be explored and their impacts on the project duration can be evaluated. A real-life case example was used to demonstrate the application of the framework. The results indicate that risk management can systematically be incorporated into scheduling. The impact of multiple risks on activity time contingency can effectively be estimated. The robustness of the schedule can be enhanced through iterative response planning. The newly developed framework thus provides construction planners with a practical tool for proactively assessing the impact of the project-specific risks on major milestones and project deadlines. This study advances the current practice of time contingency estimations by introducing an integrated approach for risk management and project scheduling. It also advances the application of fuzzy sets theory in assessing impact on activity durations subjected to multiple risks.

One of the key factors for enabling sustainable construction is promoting the acquisition of knowledge about sustainable construction practices (SCPs). Information retrieval (IR) is at the heart of knowledge acquisition. However, retrieving the right information about SCPs for the right context is not an easy task; information about SCPs is complex, interdisciplinary, multifaceted, and context sensitive. To enhance the process of IR, there has been recent calls for an information systems epistemology (the theory of knowledge and knowing) to support enhanced design and use of information systems based on a better understanding of knowledge and knowing. To address this need, this paper proposes an epistemology-based semantic model for representing and reasoning—in a context-aware manner—about the knowledge of SCPs and the process of knowing (i.e., acquiring) this knowledge. The proposed semantic model of SCPs is composed of a hierarchy of concepts, interconcept relations, and axioms. The model is intended to facilitate domain-specific, context-aware retrieval of information about SCPs. The model was evaluated through answering competency questions, automated consistency and redundancy checking, expert interviews, and application-oriented evaluation. The model was implemented in an IR system and has shown to improve the retrieval results significantly. This research contributes to the body of knowledge by offering an epistemology-based semantic model for supporting the retrieval of more relevant and specific information based on multidimensional contexts. The model, and its implementation in the IR system, would allow construction professionals, stakeholders, and information users to retrieve more relevant information about SCPs, which would in turn support enhanced decision making.

Accelerated contract provisions (ACPs) such as cost-plus-time ($A+B$) and incentives/disincentives (I/D) are increasingly common, yet very little is known about their pure time-cost performance effects on change orders. To fill this large knowledge gap, a two-stage research methodology drawing on 1,372 highway improvement projects completed in California was adopted for this study. The Stage I study investigated the marginal change-order impacts of two ACPs, pure $A+B$ and I/D combined with $A+B$. How ACP change orders affect projects’ time-cost performance was numerically modeled and successfully validated over the Stage II study. The results clearly showed that both ACPs led to more schedule-change and cost-change orders than conventionally contracted projects, whereas I/D combined with $A+B$ performed significantly better than pure $A+B$ in terms of the magnitude of schedule-change orders. This conveys an important recommendation to state transportation agencies (STAs) that $A+B$ be used with an I/D provision. The results and numerical models of this study would help STAs better assess and justify the impact of change orders on the duration and cost of projects, enabling them to more effectively use contingency amounts. Use of the models can also benefit contractors requesting a change order because the models can provide them with advanced knowledge of the probable time-cost growth rates specifically for the pursued ACP.

A temporary structure serves mainly to protect permanent building structures from the natural environment during the construction operation. When exposed to the natural environment, a temporary structure should effectively resist the variations in external factors that exist at construction sites. The objective of this paper is to provide a methodology for creating robust design alternatives for temporary construction in value engineering (VE). A combined effort is presented by integrating the problem-solving principles of theory of inventive problem solving (TRIZ) in conjunction with robust design. In this approach, the design parameters are planned to minimize the impact of external factors on the intended design functions of temporary structures; consequently, a new alternative is selected to be more robust to withstand the surrounding site conditions. A case study conducted on a retaining wall and its related temporary structures demonstrated that the creation of robust design alternatives can be achieved by integrating the problem-solving principles with the external factors in robust design.

Major infrastructure and construction (MIC) projects are those with significant traffic or environmental impact, of strategic and regional significance and high sensitivity. The decision-making process of schemes of this type is becoming ever more complicated, especially with the increasing number of stakeholders involved and their growing tendency to defend their own varied interests. Failing to address and meet the concerns and expectations of stakeholders may result in project failures. To avoid this necessitates a systematic participatory approach to facilitate decision making. Though numerous decision models have been established in previous studies (e.g., ELECTRE methods, the analytic hierarchy process and analytic network process) their applicability in the decision process during stakeholder participation in contemporary MIC projects is still uncertain. To resolve this, the decision rule approach is employed for modeling multi-stakeholder multi-objective project decisions. Through this, the result is obtained naturally according to the rules accepted by any stakeholder involved. In this sense, consensus is more likely to be achieved because the process is more convincing and the result is more easily accepted by all concerned. Appropriate rules, comprehensive enough to address multiple objectives while straightforward enough to be understood by multiple stakeholders, are set for resolving conflict and facilitating consensus during the project decision process. The West Kowloon Cultural District (WKCD) project is used as a demonstration case and a focus group meeting is conducted in order to confirm the validity of the model established. The results indicate that the model is objective, reliable and practical enough to cope with real world problems. Finally, a suggested future research agenda is provided.

This paper presents the mixed-integer nonlinear programming (MINLP) model for nonlinear discrete optimization of project schedules under restricted costs. The proposed model includes cost-objective function, generalized precedence relationship constraints, project duration restraints, logical conditions, and cost restrictions. The MINLP model allows inclusion of a wide variety of nonlinear expressions and provides the exact optimal output data for construction project management, such as a Gantt chart, histogram, and S-curve of total project cost. The novelty of the contribution is that the planner is now enabled to perform the exact optimal scheduling of project activities simultaneously with scheduling of nonlinearly restricted total project cost at each discrete working time unit. At this point, the restrictions can be set on increments and cumulative values of total project cost. A set of application examples is shown in this paper to demonstrate the advantages of the proposed model.

As a new delivery mode, integrated project delivery (IPD) relies on highly trust-based collaboration among project parties. Thus, selecting the appropriate parties is important for successful IPD. Although traditional selection methods, which are primarily based on only the lowest tender price or multiple criteria other than price, can help select parties that can complete an integrated project, they are not completely suitable for IPD when trust and collaborative relationship among the project parties are considered. To improve upon this shortcoming of established methods, a new method based on the concept of an interorganizational transactive memory system (I-TMS) is established in this paper. The I-TMS drives group members to be mutually trusting and cooperatively integrate their professional knowledge, which reflects the idea of collaboration that underlies IPD. In this study, party selection for IPD was achieved via two processes. First, this study developed an I-TMS rating scale and conducted a questionnaire-based analysis to verify its reliability and validity quantitatively. Second, this study selected an appropriate combination from seven combinations of party candidates. In addition, this study analyzed the appropriate combination using social network analysis (SNA). The results suggest that project parties with a low I-TMS degree should engage in frequent interaction to foster mutual cognition and trust and improve team collaboration for IPD.

Despite the importance of project deadlines and resource constraints in construction scheduling, very little success has been achieved in solving the resource-constrained discrete time–cost trade-off problem (RCDTCTP), especially for large-scale projects. In this paper a new heuristic method is designed and developed to achieve fast and high-quality solutions for the large-scale RCDTCTP. The proposed method is based on the novel principles to enable effective exploration of the search space through adequate selection of the activities to be crashed for a resource constrained schedule, by only crashing the activities with zero float in a resource constrained-schedule, which form the critical sequence. The computational experiment results reveal that the new critical sequence crashing heuristic outperforms the state-of-the-art methods, both in terms of the solution quality concerning project cost and computation time. Solutions with a deviation of 0.25% from the best known solutions are achieved within seconds for the first time, for a large-scale project including up to 2,000 activities. The main contribution of the new heuristic to practitioners and researchers is that it provides a fast and effective method for optimal scheduling of real-life-size construction projects with project deadlines and resource constraints.

Teams that deliver complex transportation construction projects need tools that manage risk and allow for successful delivery. Construction manager/general contractor (CM/GC) project delivery is an alternative method that furnishes public agencies with an attractive option for delivering projects in a less adversarial and more constructive manner by involving the contractor during the design phase. This paper identifies the effects of CM/GC delivery on construction process risk. Owners, contractors, and design engineers with sizable CM/GC experience on transportation-related projects were surveyed to identify differences in the perception of CM/GC processes, especially compared to design-build and design-bid-build project delivery methods. The perceived benefits and disadvantages regarding quality, schedule, cost control, and collaboration/flexibility are discussed. The benefits include strategies for robust process risk management and successful project delivery, while the disadvantages expose barriers of implementation that must be overcome. Ultimately, this research identifies differences in how project teams value CM/GC processes with regard to minimizing construction process risk, thus enabling teams to more effectively facilitate unity and strengthen the CM/GC process.

The international construction market has significantly grown in the past decades, and it has created new opportunities for engineering and construction firms to expand their businesses into foreign countries. However, this market is primarily riskier than the domestic market because of differences of political, economic, social, cultural, and business environments. Because firms are profit-seeking entities, it is vital for them to explicitly understand those risks in both macrodimensions and microdimensions such as country level and project level, and they must be well prepared to assess and mitigate those risks to successfully gain the anticipated profits. The goal of this paper is to empirically analyze the host-country effects (i.e., macrolevel risks) on the profitability of international engineering and construction projects. A total of 2,821 projects completed by Korean engineering and construction firms from 1993 to 2012 were analyzed using the variance-component model. The results show that (1) host-country effects contribute to the profitability of projects indirectly (interaction with firm capabilities) rather than directly (independently); (2) host-country effects are more evident in booming periods than in recession or transition periods; (3) host-country effects are greater in less-developed countries than in developed countries; and (4) host-country effects are more significant for large firms than for small-medium firms. The findings of this paper are also significant in that they provide a data-driven strategic guidance for top managements of international firms, particularly for their country diversification planning and country portfolio management. The process and methodology used in this paper is repeatable, and it can be directly adopted by international firms in the construction industry for a macrolevel-risk analysis of their future international projects.

Substantial research has been performed on data standards and exchanges in the AEC/FM (Architecture, Engineering, Construction and Facilities Management) industry over the past several years. The growing popularity of Building Information Modeling (BIM) technology is based heavily on the perception that it can facilitate the sharing and reuse of information during a project’s lifecycle. Although many researchers and practitioners are in agreement about the potential applicability and benefit of BIM in construction, it is still unclear why BIM is adopted, and what factors enhance the implementation of BIM. Thus, BIM acceptance and use remains a central concern of BIM research and practice. BIM was accepted in the United States earlier than in Korea, and BIM users are expected to have a higher maturity and positive perception about utilizing BIM depending on a lengthier utilization period. This means that the mechanism for achieving acceptance of BIM in Korea differs from the mechanism in the United States. Therefore, Korea’s BIM acceptance model was compared to that in the United States using structural equation modeling. The key components, including the BIM acceptance model, were identified through a literature review of the Technology Acceptance Model (TAM) and related theories and was consolidated by interviews and pilot studies with professionals in the construction industry. Based on these components, a questionnaire was designed and sent out to workers in construction organizations (such as contractors, architects, construction managers, engineers, and facility managers) in Korea and the United States. A total 164 completed questionnaires were retrieved. Structural equation modeling for hypothesis testing was conducted using commercially-available software. The results from this study can serve as a foundation for research looking into the organizational context to further BIM acceptance in the construction industry. The comparison of the mechanism and subsequent results will serve as a guideline for developing an acceptance strategy that is suitable for Korea.