Journal of Construction Engineering and Management

Despite a decrease in industry level measures in construction productivity, there has been a steady increase in construction productivity at the activity level. This research examines equipment technology as one factor that may explain that increase. The relationship between changes in equipment technology and partial factor productivity is examined for 200 activities over a 22 year time period. Specifically, the paper examines the relative impact of different types of equipment technology for five technology factors: energy, control, functional range, information processing, and ergonomics. Through ANOVA and regression analyses, it is found that activities that experienced a significant change in equipment technology also witnessed substantially greater long-term improvements in partial factor productivity than those that did not experience a change.

This article presents a generic project risk management process that has been particularized for construction projects from the point of view of the owner and the consultant who may be assisting the owner. The process could also be adapted to the needs of other project participants, and many points referred to in the article can be directly applied to them. Any project risk management process must be tailored to the particular circumstances of the project and of the organization undertaking it. First, the article explains a complete or generic project risk management process to be undertaken by organizations with the highest level of risk management maturity in the largest and most complex construction projects. After that, factors influencing possible simplifications of the generic process are identified, and simplifications are proposed for some cases. Then the application to a real project is summarized. As a final validation, a Delphi analysis has been developed to assess the project risk management methodology explained here, and the results are presented.

Modern infrastructure systems are highly developed, with considerable capital funding invested in them. While capital is spent on new infrastructure initiatives, the maintenance of the present infrastructure must not be neglected. Increasingly, public agencies are being urged to develop improved systematic methodology for allotting their period budgets more appropriately so that the capacity of the installed infrastructure is more fully utilized and sustained. When planning the allocation of investment funds, multiple objectives may exist that are dependent on the constraints, resources available for construction, and the interrelationships and dependencies among all of the alternatives. This makes the task of planning, prioritizing, and allocating funds a complex exercise. This paper presents a financial outlay model called PRISM, Proactive Rehabilitative Sewer Infrastructure Management, which uses linear programming to optimize allocation of funding for the local sewer network maintained by the City of Edmonton, Canada. By grouping sewer pipes into categories based on parameters of age, diameter, material type, waste types, and average depth of cover, the model provides a mechanism for determining the most appropriate allocation or appropriation of funding given a planning horizon and budgetary constraints.

The Performance Information Procurement System (PIPS) was tested on the procurement of the $2.96 million Bridgerland Academic Training Center (ATC) for the state of Utah Division of Facilities Construction Management. The artificial intelligence (AI) information based PIPS was run two ways—selection with biased subjectivity (similar to current best value processes) and without biased subjectivity. Unlike other best value processes, PIPS minimizes the decision-making and subjective bias of the owner’s representatives. The procurement test at Bridgerland ATC provides a comparison between the AI selection versus the user agency’s subjective prioritization. The result of the system was one of the “best” construction projects procured at the state of Utah (on time, on budget, high quality), with no contractor generated change orders for additional cost, minimized construction management requirements, and high customer satisfaction.

This paper describes a model for use in predicting potential cost overruns on engineering design projects. The output of the model is useful in assessing the amount of possible risk on a project and the likelihood of making a profit on the job. The model is intended for use by engineering consultants, i.e., structural, mechanical, and electrical engineers, in the building design industry. This research uses fuzzy logic to model the relationships between the characteristics of a project and the potential risk events that may occur, and the associated cost overruns caused by combinations of the project characteristics and risk events. This paper discusses the topic of scope creep and scope definition, which are significant causes of cost overruns on design projects; identifies the project characteristics and risk events used in the model; explains the structure of the model and the use of fuzzy logic; and provides recommendations for future research.

Current scheduling practices in precast plants are fairly basic and depend greatly on experience. This may lead to inefficient resource utilization, over-inventory, and/or missing delivery dates. Computer assisted scheduling may therefore be useful in producing better production schedules. This paper shows how constraint programming (CP) can be applied in production scheduling for precast plants. The paper describes a constrained precast scheduling model that incorporates the key constraints and objectives considered by production schedulers. A capacity-based backward-scheduling earliest due date rule and a CP approach are developed to solve the model. The CP approach is computationally efficient, even though it incorporates many problem-derived constraints. The efficiency of the CP approach lies in the fact that the representation (model) is separated from the algorithm (solver). Strategies to improve the performance of the CP approach are identified, and the CP approach is compared against commonly used heuristic rules on an example problem.

Construction has typically been viewed as a production process, with the product being the completed facility. In addition to providing this product, contractors also provide service. Construction is examined in terms of the service product, service delivery, and service environment. The concept of service encounters is examined in the context of perceived quality and customer satisfaction. Determinants of service quality are analyzed in terms of how they influence perceived quality. The relationship between the criteria used by customers in choosing suppliers and the factors driving satisfaction are examined, and results of two studies of factors involved in contractor selection and satisfaction are reviewed. These factors are the contractor-customer relationship, the contractor's project management skills, the contractor's safety performance, whether the contractor has a prepared/skilled workforce, and the cost of the work.

A discussion about movies used to monitor activities on a construction site is presented. A new concept in time-lapse photography is introduced, where the user records pictures of a construction site shot at an optimal frame rate and is able to playback time-lapse movies at lower frame rates, this way adjusting the running time and detail of the playback movie. A software package is built in the Windows visual environment, capable of generating a time-lapse movie of a desired frame rate from a regular digital movie shot at the construction site. The selection of the most appropriate frame rate to handle different managerial issues such as analyzing claims, investigating accidents, and monitoring progress is discussed. Solutions are sought to the problem of storing the vast amount of digital information generated by movies, using commercially available storage devices.

This paper presents stability analysis and design recommendations for the falsework of wood and metal post shores. Based on the setup of shoring systems used on actual construction sites, analysis models of the shoring system have been derived. The experimental test results indicate that the base stiffness to the ground of shores is 50 t-cm/rad for (490 kN-cm/rad) wood post shores and 70 t-cm/rad (686 kN-cm/rad) for metal post shores of which the joint stiffness between members is 750 t-cm/rad (7,355 kN-cm/rad). With these stiffnesses, factors of 0.75 for wood post shores and 0.85 for metal post shores are used to modify the critical loads of shoring systems calculated from individual shores. The critical loads of a shoring system increase with the number of fixed strong shores, but are not affected by the number of leaning columns. In simplifying shore design, the LeMessurier formula is used for the strength computation of shoring systems composed of wood post shores. The critical loads of shoring systems increase linearly with the number of strong shores, but they are invariant with the positions of strong shores. If the required number of strong shores is defined, the critical loads of shoring systems can be found by interpolation.

The line-of-balance (LOB) method of scheduling is well suited to projects that are composed of activities of a linear and repetitive nature. The objective of this study is to set down the basic principles that can be used in the development of a computerized LOB scheduling system that overcomes the problems associated with existing systems and creates solutions to problems encountered in the implementation of repetitive-unit construction. The challenges associated with LOB scheduling include developing an algorithm that handles project acceleration efficiently and accurately, recognizing time and space dependencies, calculating LOB quantities, dealing with resource and milestone constraints, incorporating the occasional nonlinear and discrete activities, defining a radically new concept of criticalness, including the effect of the learning curve, developing an optimal strategy to reduce project duration by increasing the rate of production of selected activities, performing cost optimization, and improving the visual presentation of LOB diagrams.