Journal of Construction Engineering and Management

A dynamic planning and control methodology is developed by integrating the applications of axiomatic design concepts, concurrent engineering concepts, the graphical evaluation and review technique (GERT), and the system dynamics modeling technique. The goal of the proposed methodology is to help create a dynamic project plan for design/build fast-track civil engineering and architectural projects where unforeseen changes can be absorbed in the project schedule without creating major interruptions. The axiomatic design concepts are applied to formulate and evaluate various work methodologies, and to create a project plan based on the selected work methodology. The concept of concurrent engineering is adapted to develop a fast-tracking framework based on the task production rate, the upstream task reliability, and downstream task sensitivity to the upstream error. The GERT diagramming scheme is used to calculate the project duration probabilistically by incorporating the possible branches and loops in the project. The system dynamics modeling technique is applied to analyze the causality links of relevant factors in the construction system, and further identifies the important variables that determine the success of a particular overlapping strategy. Consequently, with a rigorous and systemized methodology to help project planning, potential problems can be addressed early before construction. The overall increase in productivity and efficiency as a result of a better planning process can consequently promote the competitiveness of the construction industry.

Optimizing resource utilization can lead to significant reduction in the duration and cost of repetitive construction projects such as highways, high-rise buildings, and housing projects. This can be achieved by identifying an optimum crew size and interruption strategy for each activity in the project. Available dynamic programming formulations can be applied to provide solutions for this optimization problem; however, their application is limited, as they require planners to specify an arbitrary and an unbounded set of interruption options prior to scheduling. Such a requirement is not practical and may render the optimization problem infeasible. To circumvent the limitations of available formulations, this paper presents an automated and practical optimization model. The model utilizes dynamic programming formulation and incorporates a scheduling algorithm and an interruption algorithm so as to automate the generation of interruptions during scheduling. This transforms the consideration of interruption options, in optimizing resource utilization, from an unbounded and impractical problem to a bounded and feasible one. A numerical example from the literature is analyzed to illustrate the use and capabilities of the model.

This paper presents a mathematical model for resource scheduling considering project scheduling characteristics generally ignored in prior research, including precedence relationships, multiple crew-strategies, and time cost trade-off. Previous resource scheduling formulations have traditionally focused on project duration minimization. The proposed model considers the total project cost minimization. Furthermore, resource leveling and resource-constrained scheduling have traditionally been solved independently. In the new formulation, resource leveling and resource-constrained scheduling are performed simultaneously. The proposed model is solved using the patented neural dynamics model of Adeli and Park. A case study is presented to demonstrate the performance of the method under various resource availability profiles.

Since contractors' bidding behaviors are affected by numerous factors related both to the specific features of the project and dynamically changed situations, bidding decision problems are highly unstructured. No clear rules can be found in delivering a bidding decision. In this problem domain, decisions are commonly made based upon intuition and past experience. Case-based reasoning (CBR) is a subbranch of artificial intelligence. It solves new problems by matching against similar problems that have been encountered and resolved in the past. It is a useful tool in dealing with complex and unstructured problems, which are difficult if not impossible to be theoretically modeled. This paper presents a case-based reasoning bidding system that helps contractors with the dynamic information varying with the specific features of the job and the new situation. In this system, bid cases are represented by sets of attributes derived from a preliminary survey of several experienced bidders, focusing, respectively, on two reasoning subgoals: (1) Risk; and (2) competition. Through the system, similar cases can be retrieved to assess the possible level of competition and risk margin. A hypothetical example is explained and evaluated to demonstrate the feasibility of the method. The effectiveness of this system is tested by a Monte Carlo simulation in comparison to the conventional statistical method.

This paper describes the status of development and initial field test results of an innovative roller-mountable asphalt pavement density sensor. This concept measures the density of asphalt in real time using a differential microwave signal approach. Two antennas, one in front of a roller and the other behind it, measure reflected microwave signals from the asphalt, and a change in signal variability shows the operator when optimal compaction has been reached. This technique minimizes the need to quantify the hot mix asphalt properties that change during the compaction process. Several field studies have been conducted as part of this study to investigate microwave properties of asphalt pavement. Additionally, laboratory experiments were conducted at Vilnius University to better understand the electrodynamical properties of hot mix asphalt pavement. This paper briefly discusses the current asphalt density measurement approaches. This is followed by a description of the prototype design, construction, and subsequent field testing. Initial results show that this new approach has promise and that additional refinement is necessary. Future recommendations for enhancing this innovative asphalt pavement density sensor are also discussed.

The control of dust on construction sites is an issue of concern of many communities that experience a high level of construction activity. Dust suppression typically involves using large water trucks to spray haul roads, material stockpiles, and other areas being worked by equipment. This method of dust control leads to labor, operating, and safety costs and complications that can limit and sometimes prohibit its implementation. Other spray methods that are cost-effective, easy to implement, functionally viable, and safe are needed that provide direct and effective dust control for each piece of equipment. This paper describes a research project to develop and evaluate a water spray system for suppressing dust emissions that is attached directly to a piece of earthmoving equipment, specifically a dump truck. The system consists of distribution hose, pipe, and spray nozzles attached to the perimeter of the truck body, and a water pump and water tank secured to the truck's frame. The system's design takes into account various operational and performance factors, including water consumption rate, spray configuration, equipment function and operation, dust suppression effectiveness, and cost of installation and use. It is expected that the system developed can play an effective role in minimizing dust emissions from construction sites.

Delay is one of the most common problems in the construction industry. This paper presents a method for computing activity delays and assessing their contributions to project delay. The method consists of a set of equations, which can be easily coded into a computer program that allows speedy access to project delay information and activity contributions. The proposed method contrasts the as-planned and as-built schedules. It is not based on critical path analyses; therefore, it does not require the calculation or updating of the critical path, and it is even not necessary to update the as-planned schedule, as required by the traditional delay analysis methods. The results calculated from the proposed method include various variations of activity schedules and their contributions (in days) to the overall project delay. They provide an objective baseline for determining responsibilities of delays. The method can be integrated into any delay analysis system to further improve and automate the construction delay analysis process. Practical examples are used to illustrate the computation mechanism.

The focus in this paper is on a system, developed by the writers, called VIRCON (short for VIRtual CONstruction), in which the traditional construction planning is combined with 3D/4D models of the project. To facilitate current best practices with 3D/4D models of the project, VIRCON has been implemented using object-oriented programming, client/server configuration, database management information, and CAD systems. The real innovation in the design of VIRCON is associated with the unique scheduling and simulation engine developed to integrate cost planning and scheduling and accommodate integrated cross-impact analysis. VIRCON has been validated by means of student group projects on a course where many of the project management techniques are being taught. The teaching approach conducted with the utilization of VIRCON has shown the way forward in creating a dynamic and interactive learning atmosphere. This paper also outlines the experience gained from teaching construction planning fundamentals by means of the VIRCON system.

The construction industry in China is developing toward the international procurement practice, and such development has attracted many foreign firms into the Chinese construction market through the formation of Sino-foreign joint ventures. Joint venture has become an important sector in the Chinese construction industry. However, the difference in management systems, technological practice, and cultural background among the partners within joint ventures brings difficulties to the function of joint venture. A significant degree of risk is involved in joint venture investments. Thus, foreign firms increasingly intend to spend more effort in studying proper strategies of managing risks in their joint venture businesses. Based on a survey, this paper establishes a risk significance index to show the relative significance among the risks associated with the joint ventures in the Chinese construction procurement practice. Real cases are examined to show the risk environment faced by joint ventures. The paper also investigates practical applications of risk management in the business of joint ventures.

To successfully compete in the long term, a company must be sure current customers are satisfied. Providing superior quality and keeping customers satisfied are rapidly becoming the ways companies differentiate themselves from competitors. This study examines empirically home builders' performance as measured by the degree of home buyers' satisfaction. Sixteen Florida-based home builders agreed to participate in the study and to allow contact with their recent home buyers. Nearly 300 of these home buyers provided valuable input to the study. A model was proposed, describing home-buyer satisfaction as a three-dimensional composite of satisfaction with house design, house quality, and service. All three dimensions were found to be significant predictors of overall home-buyer satisfaction. Service emerged as the most important component in shaping the overall satisfaction. However, service was the area in which home builders demonstrated the poorest performance. The study results suggest that service deserves the most attention. It can have a far-reaching positive influence on home-buyer satisfaction.