Journal of Construction Engineering and Management

This paper introduces concepts of organizational learning and how they relate to construction contractors. It also presents the results of a survey conducted to establish the learning practices of construction contractors that operated in the United Kingdom and focuses on the use of learning mechanisms that help corporate establishments address their need for continuous improvement. The results show a low use of various forms of learning mechanisms and provide a general insight into learning practices of construction contractors surveyed. It also sheds light as to why construction contractors may be described as slow in adapting to their changing business environment. The paper urges construction contractors to move forward into a culture of learning to increase their ability to innovate and ensure continuous improvement demanded in today's dynamic business environment.

Change orders are a source of many disputes in today's construction industry. The issue at hand is whether or not the execution of change orders work has a negative impact on overall labor efficiency on a construction project. Previous literature demonstrates evidence that change orders affect labor efficiency. Attempts have been made to quantify these impacts by many researchers, with limited success. Using the electrical construction industry, a research study has been conducted to quantify the impacts of change orders on labor efficiency. In this paper, results of hypothesis testing and regression analysis are presented. A linear regression model that estimates the loss of efficiency, based on a number of independent variables, is also presented. The independent variables used in this model are (1) qualitative and quantitative criteria used to determine whether projects are impacted by changes or not; (2) the estimate of change order hours for the project as a percentage of the original estimate of work hours; (3) the estimate of change order hours for the project; and (4) the total number of years that the project manager had worked in the construction industry. Additional projects were used to validate the model, with an average error rate of 5%. The results of this research study are useful for owners, construction managers, general contractors, and electrical specialty contractors, because they provide a means to estimate the impact of a change order under certain project conditions. This research also identifies factors, which, when understood and effectively managed, may be used to mitigate the impact of a change order on project costs and efficiency.

Diaphragm walls are built to exclude earth and water from an area so that work may be performed under reasonably dry conditions. The range of applications for diaphragm walls includes earth-retaining and load-bearing walls for a variety of constructs such as underpasses, deep basements, underground stations, tunnels docks, and pump houses. In traditional construction methods, the concrete diaphragm wall consists of separate panels, which are not formed as a continuous monolithic construction. Vertical joints are used to divide the wall into panels, and horizontal reinforcement is not continuous from one panel to the next. Recently, a diaphragm wall, believed to be one of the largest ever built, was successfully constructed in Egypt with a continuous horizontal reinforcement. This paper describes in detail a new construction method for a diaphragm wall system. In addition, the difficulties encountered during construction are highlighted. Movements of the wall during excavation are reported. A comparison between the new and traditional construction methods is carried out in terms of cost and schedule. Applying the method presented in this paper offers substantial opportunity for reducing the steel reinforcement requirement and eliminating the use of shoring systems or ground anchors.

In the purchase of a constructed facility, the buyer values those components that are in place when the user occupies the building. A task of placing or assembling such a component is therefore “value-adding” (VA). This paper presents a method to classify construction tasks as VA, contributory, or ineffective to assess the value-added by individual activities, as well as the aggregate value-added effectiveness of the construction plan. Current approaches to evaluate construction operations are based on limited examples rather than general rules. The proposed method presents a list of nine rules that are applicable to various construction trades. This paper provides for the value-added classification rules, specifies how to decompose activities for value-added analysis, and presents an illustrative test case. The proposed method can be used to assess the overall planned effectiveness of a detailed construction plan or the actual effectiveness of a construction operation. A case study of masonry wall construction indicates that the method requires significant understanding of the evaluated operation and task precedence relationships to classify activities properly. The use of this method for construction plan assessment enables a contractor to identify and potentially eliminate or reduce non-VA tasks, as well as predict the value-added effectiveness of a plan.

There is tremendous growth in the use of ready-mixed concrete (RMC) for construction in developing countries. In Saudi Arabia, the production and use of RMC is now widespread, but the quality of concrete construction is still generally substandard. The RMC industry is not regulated or monitored. This has contributed to a general disregard for the basics of good quality as well as cheating by some RMC producers. To rectify the situation and to improve the performance of RMC producers, systematic external monitoring and inspection is required. Recently, the Municipality of Riyadh has started implementing a mandatory quality scheme for RMC plants operating in the city. The scheme was designed considering the difficulties and constraints common to implementing a quality scheme in developing countries. This paper gives details of the quality scheme as developed for RMC in Riyadh, Saudi Arabia. Specifically, the scheme's objectives, its elements, as well as the major difficulties and challenges encountered during its development and implementation are highlighted and discussed. This scheme's impact on the performance of RMC producers and the quality of concrete produced during the first two years are presented. The implementation of the scheme has resulted in tangible improvement in all aspects of RMC operation and product quality. Based on the experience and progress achieved so far, it can be concluded that a mandatory quality scheme can be introduced successfully into the existing RMC industry in developing countries with immediate benefits to the industry and its customers.

The paper reports the findings of an investigation into the psychosocial aspects of the work of construction project managers (PMs) in the United Kingdom. A theoretical model, which identified the different variables that may influence the behavior and effectiveness of PMs was developed. This study has used an adapted form of the behaviorally anchored rating scales (BARS) to measure a PM's effectiveness. The technique yielded five behavioral dimensions by which a PM's role may be described, and it was used in a survey involving 62 PMs. Analysis of the data suggests that a PM's effectiveness was influenced by situational and personal variables. The results strongly suggest that by understanding the complexity of such relationships, construction firms can influence the direction and behavior of PMs. The results also suggest that the behavior of PMs and project performance varied independently.

This paper examines the characteristics of discrete-event simulation systems in terms of their application breadth (general or special purpose), modeling paradigm (process interaction versus activity scanning), and flexibility (programmable or not). Several construction simulation systems are examined with primary emphasis on CYCLONE and STROBOSCOPE as representatives of the wide range of tools that are currently available. CYCLONE is a well-established, widely used, and simple system that is easy to learn and effective for modeling many simple construction operations. STROBOSCOPE is a programmable and extensible simulation system designed for modeling complex construction operations in detail and for the development of special-purpose simulation tools. The characteristics of these systems, as well as other recent developments, illustrate that an effective general-purpose simulation tool for construction is in essence one based on extended forms of activity cycle diagrams and the activity scanning modeling paradigm. As explained through several examples, these representations are indeed the most convenient and intuitive for construction simulation systems. Furthermore, the programmability of such a system is the principal factor that determines its power, flexibility, and ease of learning and use.

This paper identifies the risk factors associated with international construction joint ventures (JVs) from and “integrated” perspective. The risk factors are grouped into three main groups: (1) Internal; (2) Project-specific; and (3) External. It examines the most effective mitigating measures adopted by construction professionals in managing these risks for their construction projects in East Asia. Based on an international survey of contractors, it was found that the most critical risk factors exist in the financial aspects of JVs, government policies, economic conditions, and project relationship. When entering a foreign construction market in the form of a JV, a foreign construction company could reduce its risks if it would carefully select its local partner, ensure that a good JV agreement is drafted, choose the right staff and subcontractors, establish good project relationships, and secure a fair construction contract with its client.

A major part of the building control system in any country has to do with quality assurance (QA) of building the process and the products. As in many other countries, the government of the Hong Kong Special Administration Region delegates part of its statutory role to statutory agents to deal with the QA function. As a case study in the context of the Hong Kong construction industry, the relationship between QA and the role of statutory agents is investigated. An authorized person (AP), normally an architect, is the statutory agent as an integral part of the property development control system in Hong Kong. Although AP's statutory roles have already been recognized, their formal roles in respect of QA have never been studied. This paper, being supported by a research project carried out in 1997, presents the result of a study on the relationship between the QA system and the AP practice. The research revealed that in the APs' professional practice most of them have a basic concept and awareness of QA. Their checklists to run projects are similar to a QA manual. To discharge their statutory duties APs are already performing most of the QA standards similar to the ISO 9001 requirements. This paper concludes that the ISO 9000 requirements could be an extra administrative burden to a statutory agent.