Journal of Construction Engineering and Management

A delay claim often occurs when a difference between the actual completion date and the contract completion date exists. The duration of a delay is an essential piece of information required for determining the cause of a delay. However, it is difficult to analyze a delay claim due to the fact that numerous factors that cause this delay, thereby making it a very complex issue. One of such factors is the lost productivity or loss of productivity. Despite the fact that it is one of the major causes of delay, there have been only a few studies that focus on converting lost productivity into delay duration carried out to date. Claims for productivity losses are generally the result of tension between the contractor and the owner. This tension arises due to the great difficulty involved in quantifying disruption effects. Thus, to calculate accurately the delay duration, a logical method for analyzing schedule delay caused by lost productivity is necessary. Therefore, in this study, we propose a method for analyzing construction schedule delay where this lost productivity is taken into consideration. This methodology was implemented on a case project to ascertain its practicability, and to decide whether it can be utilized in the case of a delay claim related to lost productivity. The significance of this paper is twofold. One is the method to convert the lost productivity into the delay duration, which can be applied to reasonable delay claim settlement. The other is the process to analyze the construction schedule delay considering lost productivity.

The most common cause of construction claims is delay. Moreover, delay claims are often extremely complex and difficult to resolve. For this reason, the construction industry requires an effective and reliable method for analyzing the causes and effects of construction delay. Presently, the methods of analysis in common use do not adequately account for several commonly encountered situations. As a result, project time extensions are often considered without rigorous analysis. Therefore the objective of this study is to propose and describe an effective and logical method for evaluating construction delays that adequately accounts for commonly encountered situations. To achieve this objective, the writers propose a new methodology called “delay analysis method using delay section” (DAMUDS) as a means of overcoming two limitations of existing methods: (1) inadequate accounting of concurrent delay and (2) inadequate accounting of time-shortened activities. The DAMUDS method builds upon the widely used method of contemporaneous period analysis. The writers’ points are illustrated through the use of an example case.

Many practitioners today are faced with the task of advising clients on matters that may affect the number of project bidders. An appropriate question may be, does a restriction of bidder participation negatively impact project costs through limiting competition, and to what degree? Intuition and anecdotal evidence suggest that with an increase in the number of bidders vying for a project, the more competitive the low bid offer will be. There is little published evidence and analysis on bid competition impacting cost-effectiveness, although there are numerous reports replete with arguments, assumptions, anecdotal evidence, and bias. This paper critically evaluates public projects, bid under a condition of free, open, and unfettered competition. This paper presents a quantitative analysis of the impact of reduced competition on project bid prices. By selecting a single building type, designed by a single firm, with prebid estimates prepared from the same estimating database, over a limited time period, the investigation attempts to control model variance. The study found that reducing the number of bidders will result in increased project bid prices.

While some projects will experience changes to the contracted cost by deduction or additions, construction cost overruns are becoming a common problem in the construction industry. Steps need to be taken to minimize cost overrun through cost and quality control techniques. This paper presents a study conducted to evaluate construction cost overruns of asphalt paving operations performed by the Illinois Department of Transportation (IDOT). The main objective is to analyze the main causes of cost overruns and evaluate the amount of cost overrun of asphalt paving operations, using statistical process control (SPC) techniques. Real data from projects in the year 2000 were collected from IDOT. These data contain cost information of 219 projects. The results indicate that the average cost overrun for the sample collected was 4% above the bid price. Reasons for cost overruns are analyzed and a Pareto chart and a cause and effect diagram are constructed. Individuals and Moving Range (MR) control charts are developed and their interpretation and use are discussed. Furthermore, the benefits and limitations of using the individuals and MR chart in cost control applications are pointed out. It is recommended that SPC analysis be an integral part in managing and controlling project costs.

A common method used to reduce project delivery time is to overlap sequential activities. Evolution and sensitivity characterizations of design activities provide a practical tool for identifying overlapping opportunities. 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. Also, the lower the sensitivity to changes in upstream information, the less risky it is to overlap activities. A methodology for determining the evolution and sensitivity of design activities has been developed through a series of expert interviews. The evolution of an activity can be determined by evaluating the levels of design optimization, constraint satisfaction, external information exchange, and standardization. The sensitivity of an activity can be determined by evaluating activity constraints, input variables, and the level of design integration. This framework for characterizing design activities in terms of evolution and sensitivity will lead to significant reductions in project delivery times.

Planning construction site layouts involves identifying the positions of temporary facilities on site, and accordingly it has a significant impact on the safety and efficiency of construction operations. 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. This paper presents the development of an expanded site layout planning model that is capable of maximizing construction safety and minimizing the travel cost of resources on site, simultaneously. The model incorporates newly developed concepts and performance criteria that enable the quantification of construction safety and travel cost of resources on site. The present model is developed in three main phases: (1) formulating decision variables and optimization objectives in this site layout planning problem; (2) identifying and satisfying all practical constraints in this optimization problem; and (3) implementing the model as a multiobjective genetic algorithm. An application example is analyzed to illustrate the use of the model and demonstrate its capabilities in optimizing construction site layouts and generating optimal trade-offs between safety and travel cost of resources on site.

Community involvement is an important factor for sustainable highway construction. Information and communication technologies provide a new and more effective approach to facilitate community involvement. However, there are too many parameters with conflicting and subjective definitions related to sustainability and too many stakeholders with varying degrees of interest and sophistication. There is a need for an effective tool to communicate project impacts on sustainability to local communities. This paper presents an ontology for stakeholder management and sustainability in highway construction. An ontology is a conceptual semantic model that attempts to capture human knowledge (both explicit and tacit) in a consistent manner. Ontologies include three main elements: a taxonomy (common vocabulary presented in concept trees), set of relationships (linking concepts across trees), and axioms (limitation/constraints on the behavior of concepts). The ontology was used to develop a portal for broadcasting highway design features to local communities. By browsing through the portal, a user can learn about project elements, the impacts of each element on sustainability issues, who is sponsoring such element, and what efforts have been made to reduce any impacts of such elements on local communities.

Construction contractors continue to be faced with the challenge of improving productivity in order to remain successful in an increasingly competitive industry. One factor that contributes to lower productivity is absenteeism. Yet, little is known or understood about the reasons electricians miss work, and very few studies have been conducted on absenteeism in the construction industry. As a positive step to reduce the problems associated with voluntary and involuntary absences, a study was initiated to identify why workers miss work and what steps should be taken to minimize absenteeism. The main objectives of the study were to learn the reasons for absenteeism and to quantify the impacts so that solutions can be developed to help contractors improve their productivity. The study determined that managers and electricians agreed that illnesses and medical appointments were two common reasons workers missed work. However, managers also believed workers were absent because of a lack of interest or irresponsibility, while electricians reported injuries and unsafe working conditions as reasons for missing work. Furthermore, a quantitative analysis of the data revealed that when the absenteeism rate was between 0 and 5%, there was no loss in productivity. However, when the absenteeism rate was between 6 and 10%, a 24.4% loss in productivity was experienced. By understanding what causes electricians to miss work, and the effect of absences on productivity, a company can manage and control absenteeism on electrical construction projects.

There are many types of construction changes and each type can have an effect on labor productivity. To a certain extent though the specific type of change is not as important as the mere presence of the change and, as analyzed in this paper, the timing of that change. The research reported in this paper 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 are presented in this paper, representing the impact that change has on the labor productivity for early, normal, and late timing situations. The projects are a representative sample of the industry, involving a wide range of sizes, different delivery systems, and industry sectors. Late change is more disruptive of project productivity than early change, all other things being equal. The implications and benefits of this research are clear: if changes are necessary, they should be recognized and incorporated as early as possible. Practitioners can use these data and curves for either forward pricing or retrospective pricing of changes. Other researchers can use these findings to test their own findings and to explore timing issues in further detail.

Trust is an underlying psychological condition that can cause cooperation or risk-taking. Trust is considered as a predominant feature and a central mechanism in business transactions, especially among Chinese. Trust-based relationships create advantages in conducting business such as lowering cost, shortening duration, and improving performance. Indispensable conditions for trust to arise are relationships and risks. Different risks surface as a result of different levels of relationships. Sustained trust is therefore fostered by various means to counterbalance those risks. In order to assess the links between distinct trust-related features, a model is constructed and tested through a questionnaire survey in China. The findings generally support the model in terms of explaining the dominant relationships, inherent risks, and trust-fostering tools. It is recommended that firms adopt the refined model and utilize successful practices verified in this paper to foster trust and relationships and in turn secure project success.

The purpose of this paper is twofold: (1) to determine jobs/tasks associated with current injury, illness, and fatality trends in the roofing industry; and (2) to identify current safety practices associated with the prevention of these illnesses, injuries, and fatalities. In order to achieve the project objectives, a survey was designed and sent to Michigan roofing contractors. To design an adequate survey, the research team first collected background information using U.S. Bureau of Labor Statistics online database, published research, and contractor interviews. Of the 48 roofing companies asked to participate, 24 completed the survey. The survey results indicated that hand and finger injuries due to cutting operations and back injuries due to the manual handling of heavy and bulky materials to be the most frequent roofing contracting task/injury combination. Falls from elevations as well as on the same level typically occurred when carrying heavy and bulky materials such as bundles of shingles on slippery and inclined walking/working surfaces. These findings from this study may assist safety professionals in the construction industry in making effective changes for improving safety and productivity.

Previous studies between ISO 14001: 1996 Environmental Management Standard and the old ISO 9001: 1994 Quality Assurance Standard have found compatible requirements that warrant their integration. This study examines the compatibility of the revised ISO 9001: 2000 Quality Management Standard with ISO 14001: 1996 for the purpose of integration. A survey of 96 construction firms was conducted for those who were considering or were already ISO 14001: 1996 certified. Findings on the possibility/difficulty and benefits/costs of integration between ISO 14001: 1996 and ISO 9001: 2000 were obtained. Industry concerns relating to potential problems and implementation challenges were discussed. The study concludes that the revised ISO 9001: 2000 serves as an opportune platform for construction firms to consider certification to ISO 14000: 1996 through an integration exercise.