269 publications from this institution
Collaboration is an important requisite in the multi-participant building design environment. The performance of a building as an end product is enabled via the collaborative efforts of project participants. The main objective of this paper is to identify the factors that affect the collaboration among the participants in the building design process. The related data is collected from the growing literature on collaborative design. Recent technological developments that serve a higher level of collaboration and the construction industry's efforts to improve building performance are also considered. A conceptual model is proposed to address the collaborative relationship between the participants of the building design process. The challenge is to enable collaboration by integrating the work performed by participants with diverse backgrounds, varying levels of expertise, and different perspectives. The implication of this research is that a good understanding of the factors that enhance collaboration between the parties involved in design not only enhances building performance, but also improves the competitiveness of building design firms.
Increased student enrollment and the current poor state of the educational infrastructure require the construction of more school buildings and the renovation of many of the existing ones. The large number and magnitude of change orders in these projects constitute an impediment to the rapid and economic delivery of these projects. A total of 6,585 change orders filed in a school district's projects in the 5 1/2 year period from 1999 to 2004 were analyzed in five categories including owner-directed changes, code compliance issues, errors/omissions in contract documents, discovered or changed conditions, and others. The results of the study indicate that the dollar value of change orders relative to the original contract can be reduced if preventive measures are taken. These measures include choosing the right construction management firm, emphasizing the definition of project scope early in the project, and effectively managing the precontract activities by conducting value engineering and constructability reviews. The results indicate that school projects can be completed with change orders not exceeding 5% of the contract value if these measures are taken. This study is of relevance to practitioners involved in school design and construction projects.
Every bridge component has a different deterioration rate, rehabilitation cost and cost-effective treatment time. The cost-effectiveness of the timings of bridge component rehabilitation is investigated both for individual components and for combinations of components, with the objective of finding optimum bridge life and the most cost-effective rehabilitation schedule. The optimization model makes use of: (1) deterioration curves to predict the condition of bridge components with respect to bridge age; (2) benefit/cost analysis to identify the most cost-effective rehabilitation schedule. The study was conducted using Illinois data for steel bridges covering the period 1976 – 1998. The results show that the most cost-effective timings of rehabilitating individual bridge components are significantly different if the rehabilitations of different components are combined and treated as parts of a system. The results of the analysis indicate that optimum bridge life is 74 years with a best time of combined rehabilitation of both the deck and superstructure in year 44. The study is an attempt to improve current methods of scheduling bridge maintenance, repair and rehabilitation.
This paper attempts to find ways to reduce an owner's construction contingency budget such that just enough contingency is allocated that will allow the owner to deal with uncertainties but at the same time not tie up valuable funds that can be used for other activities. It is suggested that the common practice of allocating a fixed owner contingency (e.g., 10% of the contract value) to all projects contracted out by an owner is not appropriate. Instead, a methodology is proposed whereby the owner (1) analyzes historical project data; (2) identifies the line items that are problematic; (3) takes the necessary measures at the preconstruction stage to streamline these line items with respect to site conditions, time constraints, constructability issues, and project scope; and (4) finally budgets contingency funds based on this information. A case study was conducted to analyze the contingencies budgeted and actually spent by an owner in nine parking lot projects. The findings indicated that a systematic approach such as the methodology proposed in this paper is likely to minimize the owner's contingency budget.
Material selection in sustainable projects affects the environment a great deal. Selected materials gain importance as they can contaminate the environment and can produce waste during construction. Use of limited resources has also environmental impacts. Thus, considering sustainable materials in the projects and appropriate consumption of available resources are important for sustainability considerations. The danger of running out of resources and the consequences of contamination of the habitat point out to the importance of green building certification systems. Issues such as storage and collection of recyclables, waste management planning, PBT source reduction, sourcing of raw materials, material ingredients, and design for flexibility that are treated in this category are difficult to implement in developing countries, mainly because they are based on local practices. The use of materials and resources accounts approximately for 11% of the points a building can receive for LEED v4 certification. However, the use of LEED in countries other than the U.S. can be controversial as local conditions are effective in earning credentials required for certification. This study aims to review the "materials and resources" category of LEED. Comparison of local practices in selected developing countries is made based on credits in this category to provide guidelines for green projects in those countries. It is expected that practitioners in developing countries will benefit from the outcome of this study.
An integrated prediction model (IPM) was used to predict the outcome of construction litigation with the hope that it will generate a higher prediction rate than the rates obtained by using artificial neural networks (ANN), case-based reasoning (CBR), and boosted decision trees (BDTs) in earlier studies. These studies were conducted by using the same 132 Illinois circuit court cases (with slight variations in the case of the BDT and IPM studies) filed between 1992 and 2000. A prediction rate of 91.15% was obtained, higher than the 66.67% in the ANN study, 83.33% in the CBR study, and 89.59% in the BDT study. IPM involves four processes, namely, data consolidation, attribute selection, prediction using hybrid classifiers, and assessment. The performance of IPM is compared with the performance of ANN, CBR, and BDT. If the outcome of construction litigation can be predicted with reasonable accuracy and reliability, all parties involved in the construction process could save considerable money and time.
Subcontractors are very important to the successful completion of most construction projects, yet the many issues involved in subcontracting practice are seldom acknowledged. A literature review indicates that these issues include the timeliness of payments by general contractors, the process of selecting subcontractors, subcontractor bonding, construction insurance, safety issues on the construction site, partnering arrangements with various parties, and productivity issues. A questionnaire survey was administered to subcontractors, general contractors, and construction owners to investigate these issues and to determine the differences in perceptions between the parties. The results confirm the existence of the issues identified in the literature and in addition indicate that (1) the practice of retainage withheld by general contractors seems to be acceptable to many subcontractors unless its magnitude is large relative to the size of the firm; (2) postaward bid shopping by general contractors is sometimes justified, particularly in cases where the scope of subcontract work is modified; and (3) current bonding and insurance practices are adequate unless the additional transferred risks are excessive. Recommendations are made on the basis of the findings to minimize the negative effects of said issues.
Construction project managers occupy middle management positions and their performance is as important as the performance of skilled/unskilled workers to the success of a project. This study investigates the factors that motivate construction managers, identifies the dominant human values of construction managers, and explores the relationship between construction managers' human values and their motivators. A total of 101 construction managers participated in a survey to rate the importance of 20 motivators and 18 human values. Although simple correlation analysis indicated that many motivators are highly correlated with many human values, this finding ignores the interrelationships between the many variables. Factor analysis was used to reduce the 20 motivators to six motivating factors, and regression analysis was conducted to explore the relationship between each of the six motivating factors and human values, albeit without much success because of the nonlinear nature of the problem. However, by using an artificial neural network (ANN) model, it was possible to show that a relationship exists between human values and each of the six motivational factors with 75% accuracy. It is concluded that the performance of construction project managers can be enhanced by promoting motivators that agree with construction managers' human values.
Abstract Motivation is one of the key factors that stimulate individuals to improve their productivity. Therefore, motivation of construction workers has been debated with considerable interest by participants in the construction industry. However, motivating only construction workers, but ignoring the motivation of construction professionals, viz., architects and civil engineers, may not be enough to successfully complete a construction project. Although motivation of construction professionals may also enhance the performance of a construction project, this topic is mostly ignored in the motivation literature. This study attempts to fill this gap by (1) identifying the motivators that are of importance to architects and civil engineers and (2) exploring the statistical difference between architects’ and civil engineers’ motivators. For this purpose, a questionnaire survey was administered to Turkish architects and civil engineers to collect data on their perceptions of the importance of different motivators. The case of Turkey is investigated because several of the larger Turkish contractors undertake construction projects outside their home country. Statistical analysis was performed on the collected data to verify whether there are statistically significant differences in the perception of some motivators by architects and civil engineers. The study demonstrates the existence of a statistically significant difference between architects’ and civil engineers’ motivators. Identifying the architects’ and civil engineers’ motivators may help construction companies in motivating their architects and civil engineers more effectively, thus developing a quality workforce.
Purpose – Transaction costs arise from economic exchange rather than production activities. However, the term “transaction cost” is not consistently defined in the construction industry because the concept of transaction cost is not universally accepted by all stakeholders in construction projects. As a result, empirical studies are few and conflicting because accessing data on transaction costs is problematic, and the interpretation of the data is difficult. The purpose of this paper is to analyze the transaction costs borne by the owner in a construction project from the perspective of transaction cost economics and construction project characteristics. Design/methodology/approach – A questionnaire survey was administered to construction owners. The factors that impact transaction costs were analyzed in the context of human-related issues (the owner's and the contractor's positions in the transaction), and environment-related issues (the transaction environment, and project management efficiency). Statistical analyses were conducted to compare the transaction costs incurred in the pre- vs post-contract phases of a project relative to the private vs public sector, different project delivery systems, different procurement methods, and different types of contracts. Findings – The owners surveyed believe that transaction costs may be reduced if the owner and the contractor follow some basic guidelines (e.g. experience in similar projects, prompt payment, good relationship with project participants, no irregularities in bidding, and only few material substitutions and claims), if the project is well-run (e.g. technical competency, strong leadership, prompt decision-making, effective communication, and fair/speedy conflict management), and if the transaction environment is favorable (e.g. fair risk allocation, early contractor involvement, and complete design documents). The findings of the survey also indicate that post-contract transaction costs are much higher than pre-contract transaction costs expressed as percent of project value and that transaction costs are affected by the owner (public vs private), the procurement method, the project delivery system, and the type of contract. Originality/value – The primary contribution that this research makes to the body of knowledge is a better understanding of transaction costs incurred by construction owners in the USA. The highest transaction costs are to be expected in the post-contract phase of public projects awarded on a unit price basis, but can be reduced, hence reducing overall project cost.
Abstract. A new way to document and visualize the as-built condition of an urban tunnel project with high accuracy is described in this paper, based on recent developments of laser scanning technology. In traditional surveying, the components of a tunnel are organized on the basis of the location of stations and offsets along the project alignment specified in the drawings. It is difficult for people without an engineering background to understand the information involved in surveying reports, drawings, and engineering data. However, in the interest of transparency, public agencies that commission construction projects have to make project information available to government officials and to the general public. This paper discusses the combined use of laser scanning technology and web mapping services to improve the documentation and visualization of an urban metro tunnel. Laser scanning technology is introduced to perform the surveyor's task, document the as-built condition, and geo-reference the construction elements. A set of panoramic pictures is generated by laser scanning that allows for taking measurements and extracting 3D coordinates. An XML file that contains geo-reference information is appended to each panoramic picture. Using application programming interface (API), this information is referenced to a web mapping service. A case study of the CTA Red line Tunnel in Chicago, IL demonstrates this method in a real life project.
Sustainability has gained importance in the building design/construction industry due to the increase in the need for energy, the extensive use of non-renewable resources, and therefore the damage caused to the environment by traditional building design and construction. The concept of green building was developed for this reason. Green buildings can be defined as structures that consume less water, energy, and other resources while emphasizing human health and protecting the environment. While green buildings have these advantages over traditional buildings, the rate of green building production is less than expected because many barriers are encountered during the design and production of green buildings, despite the recent attention paid to sustainable practices. This research focuses on exploring the barriers encountered during green building production in Turkiye and the possible solutions for overcoming these barriers. According to the data obtained through a questionnaire survey, the most important difficulties encountered in Turkiye include the lack of government subsidies, the lack of green building regulations, the public’s indifference to green building technologies, and education and technology deficiencies. According to the respondents, the possible solutions involve government incentives, adoption of national standards and best practices, educating the public and the design/construction professionals about green buildings, and the development of novel green building technologies. The major contribution of the findings is that it highlights the fact that the stakeholders of green building projects (i.e., owners, designers, constructors, and facility managers) face important barriers and lets stakeholders recognize that solutions to overcome these barriers are available. The major implication is that the stakeholders in green building projects will likely be better prepared to deal with any barrier before undertaking green building projects in Turkiye and countries with similar socio-economic conditions.
The construction of buildings is a complex process that is carried out by a large number of participants with conflicting objectives. This complexity and fragmentation makes the management of the process particularly difficult. This paper presents an integrated system called MITOS - a multi-phase integrated automation system that has been designed primarily for design/build firms, i.e., firms or alliances of firms that do both design and construction. But the system can also be used by independent design firms and construction companies as long as they are cooperating on the same project. This integrated system allows designers as well as constructors to receive information about all aspects of the project (including clients, subcontractors, suppliers, human resources, time, design, materials, equipment, cost, communication, quality, and procurement) in the design and construction phases of the project and hence to manage the project effectively. The system makes use of a central component called ASDB - an automation system for design/build and a set of satellite programs.
