Editor’s Note

“Relative Effectiveness of Project Delivery and Contract Strategies”: Although selecting a project delivery process should be facilitated through analysis, there exists a lack of quantitative values of project delivery systems to assist the selection process, leaving project managers with no alternative but to make project delivery selection decisions on the basis of subjective evaluations. Oyetunji and Anderson present research findings that provide the quantitative values needed to aid in making this decision. Based on the determined values and an included decision analysis technique, interested parties can develop and evaluate project delivery alternatives to identify the optimal solution for a given project.

“Work Continuity Constraints in Project Scheduling”: Since the resources required to perform repetitive activities in a repetitive project move from one stage to another, a main objective of scheduling these projects is to maintain the continuity of work of these resources to minimize the idle time of resources, often referred to as work continuity constraints. Mario VanHoucke provides an extensive literature summary of this topic. In addition, VanHoucke proposes an exact search procedure for scheduling repetitive projects with work continuity constraints. Finally, the author illustrates the concepts using three examples.

“Computerized System for Efficient Delivery of Infrastructure M&R Programs:” Tarek Hegazy discusses three common approaches used by owner organizations to deliver infrastructure Maintenance and Repair programs that use in-house resources, outsource to contractors, or a combination of the two. The author then introduces a scheduling model that uses genetic algorithms to suggest the optimum combination of in-house crews and outsourcing that meets execution constraints. The model considers all the variables that relate to in-house delivery, and also incorporates a mechanism to examine the feasibility of replacing in-house resources by outsourcing to delegate execution risks at minimum additional cost.

“Object-Oriented Scheduling for Repetitive Projects with Soft Logics”: The application of network techniques of project scheduling to repetitive projects has been criticized for the inability of network techniques to help maintain work continuity. In addition, current network techniques make schedules time-consuming to develop as well as maintain. Fan and Tserng, utilizing the soft-logic sequencing principles developed by Fan in 2002, develop a system that provides an easy-input module in addition to scheduling and work-continuity-maintenance modules in order to ease the network generation and update processes. This then provides the shortest possible duration logics and the start and finish dates required to maintain work continuity.

“Total Quality Performance of Design-Build Firms Using Quality Function Deployment”: The belief that the design-build project delivery system does not lend itself to effective quality assurance and control is quite common in construction circles. Lee and Arditi describe a model that was developed to measure the total quality of a design-build firm using Quality Function Deployment. The model makes use of eight building-quality factors and three building performance factors and it measures the quality performance of the constructed facility by using QFD. The model can be used by design-build firms to benchmark themselves against their competitors or to monitor their own performance.

“Innovative Central Opening Strut System for Foundation Excavation”: A central opening strut system is used to support diaphragm walls for foundation excavation, transmitting the earth pressure acting on the diaphragm wall in one direction to the diaphragm wall in the other direction by the arch action of a polygon module. Yang, Chen, and Chen examine a construction site with five excavation stages and four layers of strut systems. By using the ABAQUS finite-element program, it is found that the proposed central opening strut system is able to provide a large working space and that it greatly increases the efficiency of the construction work.

“Use of a WBS Matrix to Improve Interface Management in Projects”: Many researchers agree that smoother construction would naturally result from better communication between designers and constructors. Chua and Godinot propose to use the concept of work breakdown structure to improve work interface management. The authors explain the concepts of work breakdown structure and interface management. It is then proposed that the concept of WBS matrix be incorporated into the construction industry and analysis be made, in a case study, of how it may be used to improve interface management.

“Success/Failure Factors and Performance Measures of Web-Based Construction Project Management Systems: Professionals’ Viewpoint”: Nitithamyong and Skibniewski present the results of an empirical study conducted to refine their previous findings on potential factors that may influence performance of commercial Web-Based Project Management Systems and potential measure that might be used to assess performance of such systems. The authors base their findings on data obtained from 39 professionals who had practical experience with WPMSs in construction projects. Forty-two factors that can affect performance of WPMSs and 36 measures that can be used to evaluate such performance are identified and classified into distinct groups.

“A Construction Business Automation System (CBAS)”: Lee and Shi introduce a system prototype, Construction Business Automation System (CBAS), for modeling and automating construction business processes by using workflow and object technologies. The development of the prototype has resulted in the creation of four technologies. These include the object-oriented reusable component technology for modeling cosntruction management tasks, the Construction Business Process Modeler based on the Task-Based Modeling methodology, the Request Driving methodology for raising business requests, and the supporting technology for interacting with a commercial workflow engine for executing business process instances.

“Fundamental Principles of Workforce Management”: For more than $25\text{years}$ , H. Randolph Thomas has been observing and writing about inefficient labor productivity practices resulting from poor site management procedures. In this writing, Thomas, with Michael Horman, aims to fill a void created by the absence of fundamental principles of site construction management. The authors use deductive reasoning to develop fundamental principles to avoid poor practices. General principles and fundamental principles related to performance measures and daily work schedule are cited.