Editor’s Note

“Method for Calculating Schedule Delay Considering Lost Productivity”: Despite the fact that lost productivity is one of the major causes of project delays, there have been only a few studies carried out to date that focus on converting lost productivity into delay duration. Claims for productivity losses are generally the result of tension between the contractor and the owner. This tension arises because of the great difficulty involved in quantifying disruption effects. Seeing the need for a logical method for analyzing schedule delay caused by lost productivity, Lee, Ryu, Yu, and Kim propose a method for analyzing this delay where the lost productivity is taken into consideration. The method aims to convert the lost productivity into the delay duration, which can be applied to reasonable delay claim settlement.

“Delay Analysis Method Using Delay Section”: Because delay claims are often extremely complex and difficult to resolve, the construction industry requires an effective and reliable method for analyzing the causes and effects of construction delay. Because present methods of analysis in common use do not adequately account for several commonly encountered situations, Kim, Kim, and Shin present a study designed to propose and describe an effective and logical method for evaluating construction delays that adequately accounts for these circumstances. The authors propose a new methodology as a means of overcoming two specific limitations of existing methods.

“Investigation of the Bid Price Competition Measured through Pre-Bid Project Estimates, Actual Bid Prices, and Number of Bidders”: Many practitioners today are faced with the task of advising clients on matters that may affect the number of project bidders. This situation presents the question of whether or not a restriction of bidder participation negatively impacts project costs through limiting competition, and if so, to what degree. Carr critically evaluates public projects, bid under a condition of free, open, and unfettered competition, presenting a quantitative analysis of the impact of reduced competition on project bid prices. The author takes special measures to control model variance in order to provide more support for his findings.

“Evaluating Cost Overruns of Asphalt Paving Project Using SPC Methods”: While some projects will experience changes to the contracted cost by deduction or addition, construction cost overruns are becoming a common problem in the construction industry. Nassar, Nassar, and Hegab present a study conducted to evaluate construction cost overruns of asphalt paving operations performed by the Illinois Department of Transportation. The study aims to analyze the main causes of cost overruns and evaluate the amount of cost overrun of asphalt paving operations, using statistical process control techniques.

“Concurrent Engineering Approach to Reducing Design Delivery Time”: Overlapping sequential activities is a common method to reduce project delivery times, and it is realized that the faster the evolution of information in an activity, the less risky it is to begin a downstream activity before the upstream activity is finalized. Bogus, Molenaar, and Diekmann present a methodology for determining the evolution and sensitivity of design activities developed through a series of expert interviews. The authors believe that this method for characterizing design activities in terms of evolution and sensitivity will lead to significant reductions in project delivery times.

“Tradeoff between Safety and Cost in Planning Construction Site Layouts”: Although available models are capable of minimizing the travel cost of resources on-site, they do not consider safety as an important and separate objective in the optimization of site layouts. El-Rayes and Khalafallah present the development of an expanded site layout planning model that is capable of maximizing construction safety and simultaneously minimizing the cost of on-site resource transportation. The model is developed in three main phases and an application example is analyzed to illustrate the use of the model. “e-Society Portal: Integrating Urban Highway Construction Projects into the Knowledge City”: El-Diraby and Wang describe the need for an effective tool to communicate project impacts on sustainability to local communities, due to the fact that community involvement is an important factor for sustainable highway construction. The authors present an ontology for stakeholder management and sustainability in highway construction. The ontology is then used to develop a portal for broadcasting highway design features to local communities.

“Factors Affecting Absenteeism in Electrical Construction”: As a positive step to reduce the problems associated with electricians’ voluntary and involuntary absences, Hanna, Menches, Sullivan, and Sargent initiate a study to identify why workers miss work and what steps should be taken to minimize absenteeism. The study aspires to learn the reasons for absenteeism and to quantify the impacts so that solutions can be developed to help contractors improve their productivity.

“Impact of Change’s Timing on Labor Productivity”: There are many types of construction change and each type can have an effect on labor productivity. The research reported by author Ibbs reaffirms that project change is disruptive and detrimental to labor productivity. Data from 162 construction projects were statistically analyzed and a series of three curves, representing the impact that change has on labor productivity, are presented. The research clearly shows that if changes are necessary, they should be recognized and incorporated as early as possible.

“Model for Fostering Trust and Building Relationship in China’s Construction Industry”: Trust is considered a predominant feature and a central mechanism in business transaction, especially among the Chinese. Different risks surface as a result of different levels of relationships. Therefore, sustained trust is fostered by various means to counterbalance those risks. In order to assess the links between distinct trust-related features, Jin and Ling construct and test a model based on results from a questionnaire in China.

“Occupational Injuries and Fatalities in the Roofing Contracting Industry”: Frericks, Abudayyeh, Choi, Weirsma, and Charles design a survey to be answered by Michigan roofing contractors in order to determine jobs and tasks associated with current injury, illness, and fatality trends in the roofing industry, and to identify current safety practices associated with the prevention of these illnesses, injuries, and fatalities. The findings from the study may assist safety professionals in the construction industry in making effective changes for improving safety and productivity.

“Integrating ISO 9001 QMS and ISO 14001 EMS for Contractors”: Pheng and Tan describe a study to examine the compatibility of the revised ISO 9001:200 Quality Management Standard with ISO 14002: 1996 for the purpose of integration. A survey of almost 100 construction firms is conducted for those who were considering or were already ISO 14001:1996 certified, upon which findings on the viability and cost of integration between the two Standards is derived.