Journal of Construction Engineering and Management

This paper describes the development and use of a new generation of planning structures that provides the basis for a superset of the traditional critical‐path method. These structures provide a means to marry critical‐path planning with linear scheduling. Attributes required of these structures for modeling projects with repetitive elements are discussed. They have been gleaned from the literature; an extended development process; and the planning, scheduling, and updating of many projects. Members of the family of planning structures include the continuous activity, the ordered activity, the shadow activity, and the cyclic activity. These activities permit the treatment of work continuity, the execution of work in an ordered location sequence, execution of work on a first‐come‐first‐served basis, and cyclic relations between predecessor and successor activities at different work locations. Their application is facilitated by the use of a generalized set of precedence relationships. Four examples are given to demonstrate the flexibility these structures offer for modeling a diverse range of project types.

One of the major inefficiencies in the use of the critical path method (CPM) in the construction industry is the large number of proprietary and commercially available software scheduling systems. This inefficiency is due, in part, to the amount of data reentry required when progress data is exchanged between members of a project team. To solve this problem, the U.S. Army Corps of Engineers coordinated the development of a data‐exchange standard with eight vendors, several construction managers, and Corps of Engineer field‐office representatives. The standard was tested on a limited basis and has been officially required by the Corps of Engineers since March of 1990. To use the data‐exchange features currently provided by software vendors, it is necessary for all participants in the data exchange to spend considerable time anticipating inconsistencies between software systems. A revised version of the format is expected to be released to vendors in early 1993. The revised version is expected to considerably reduce the time required by users to implement the exchange of project scheduling data.

The Construction Decision Support System for Delay Analysis [delay analysis system (DAS)] for personal computers is a software program that adds the capability for determining possible causes for project delays and suggests alternative courses of action to prevent further delays. The DAS is not merely another scheduling software system; it is a program that is used with existing project‐management software packages. Development of the DAS program could lead to the evolution of one “metaprogram” to address management issues. The expanded delay analysis system creates a logical‐path form of managing human and material resources in construction, built upon the solid data (foundation) of actual industrial experience and need. This paper discusses industrial participation in the development of the delay analysis system program and describes the purpose and development of the program, its technical parameters, usage, and program output. A sample case study is presented that demonstrates how the program is utilized and the type of output it provides.

This paper demonstrates detailed schedule‐ and cost‐control relationships at the activity/cost‐account level using generic microcomputer software to budget, track, and control projects. Time variances are introduced to describe differences between scheduled times and actual times for activity and project performance. Variances are the sum of more detailed variances, and variances can be calculated and reported at different levels of detail, whether for activities and cost accounts or for a project as a whole. Activity/cost‐account budgets sum to project budgets, and variances sum to project variances. A unified nomenclature and parallel budget and variance structures allow integration of cost and schedule control for projects that share common work breakdown structures. Budget, actual, and variance values of cost, progress, and time are combined in a single figure to demonstrate integration at the activity/cost‐account level. Equation development is augmented with computer implementation details for generic spreadsheets or custom applications. Examples are presented for a single element from start to completion and for a project of four elements.

The layout of temporary facilities on a construction site necessarily changes over time, so the term dynamic layout is used to describe a sequence of layouts spanning the entire duration of construction of a project. Many layout changes are dictated by the construction schedule. In the MovePlan model, which is presented here, the activity schedule is therefore augmented with data needed to construct layouts, i.e., resources required to perform activities, and their dimensions. This augmented schedule can drive the dynamic layout process, including the positioning of temporary facilities on site and the movement of materials and equipment. Conservative modeling assumptions were made in order to keep computational costs low, so that the MovePlan implementation would run on a microcomputer and thus be readily field‐usable. The MovePlan prototype system provides a graphical interactive interface with underlying consistency maintenance mechanisms. MovePlan enables users to model approximate site space needs during project scheduling and to create layouts for different stages of construction. Several strategies for creating layouts are described. MovePlan's output can be further refined by adding geometric detail and using more sophisticated graphical packages for detailed process planning. MovePlan can also be integrated with off‐the‐shelf project‐management software.

The Advanced Construction Technology System (ACTS) is a computerized data base for the classification, documentation, storage, and retrieval of information about emerging construction technologies. ACTS consists of a custom Microsoft (MS) Windows application, classification, and keyword files and a data base of emerging technologies. It currently includes technologies that relate to civil, architectural, electrical, instrumentation, mechanical, and piping systems. Technologies have been classified according to the CSI Masterformat, indexed using a predetermined set of keywords, and described according to a standard format that determines the type, amount, and organization of information about each technology. The ACTS project was supported by the Construction Industry Institute and the Construction Productivity Advancement Research program (CPAR) of the U.S. Army Corps of Engineers. Ultimately, it is anticipated that ACTS will be established as an ongoing information service to the U.S. construction industry that will help contractors, designers, and owners identify and use emerging technologies to improve construction efficiency and effectiveness. ACTS has been developed in Actor, an object‐oriented general‐purpose language for MS Windows 3.x and is available from the first writer on request.

The future success of large Japanese construction firms may well depend on the widespread implementation of computer integrated construction (CIC) concepts. Because of changes in the competitive environment, the nature of the construction industry is evolving in fundamental ways. Construction companies that emphasize CIC are likely to gain a significant competitive advantage over those that do not. In today's construction industry, information technology must be viewed as a potential resource. CIC is a strategy, incorporating computers and robotics, for linking existing technology and people in order to optimize business activity. There is no standard formula for CIC. A strategy for implementing CIC should be formulated, and each company must define its own system. The strategy must be supported and promoted at the highest company level. The objective of this paper is to describe the experiences gained in CIC research from a Japanese construction company's viewpoint, and to present a test‐base model for CIC implementation. Although the model is not a comprehensive system, it can be considered as a methodology toward total CIC.

The use of reinforced concrete in the United States is steadily increasing, and with it the need for designed and fabricated reinforcing bars (rebar). Traditionally, the detailing of the rebar is done by the fabricator, who is required to have the shop drawings approved by the civil engineer in charge of the structural design. Subsequently, the rebar is fabricated and shipped to the site where an independent subcontractor places the rebar according to the detail design. Research has shown that the delivery of construction material is strongly related to the productivity of construction processes, such as laying rebar. However, traditional rebar fabrication and shipment is geared towards minimizing the set‐up time of the rebar bending machine. As a result, rebar is cut, bent, and bundled according to shape and size without considering the sequence of placing the bars. This paper presents an alternative way to design and deliver concrete reinforcement that is based on computer integration and feature‐based design concept. Detailing data generated with CAD software is used to create rebar placement plans, shipping schedules, and assignments of lay‐down area on the construction site. Based on experiences with the application of the system, steps necessary for its implementation are discussed.

Heavy construction projects, such as dams and tunnels, closely integrate design and construction and require the project manager or the project engineer to be knowledgeable and familiar with: (1) Different types of heavy construction plant and equipment; and (2) different construction methods that may be applicable to a given project. However, to effectively define these two elements, different possible scenarios, under different conditions and constraints, must be explored with both a technology and process focus, and a resource use focus. This task requires the development of descriptive, analytical, and decision‐making models, which accurately represent and simulate these processes, and experimentation with different alternatives under different conditions. Until relatively recently, the analytical and operational tools that have been available to practitioners to achieve this, have been complex and difficult to learn and use. The Cyclic Operations Network (CYCLONE) microcomputer‐based simulation methodology presents a viable alternative to overcome these barriers. This paper describes the implementation of this system within the division of project planning and control of a large Spanish heavy construction firm, using two specific case‐study applications.

Mediating construction disputes arising from changed conditions involves reviewing contractor's estimates prior to construction, analyzing the motives for the claim and determining the owner's and designers' responsibilities. This process can be enhanced by using applicable computer‐based tools such as simulation. This paper discusses the use of simulation in the mediation process. CYCLONE models are developed to analyze part of a claim between the public owner and a steel contractor. In particular, simulation models are developed to estimate the cost of the operation as envisioned by the contractor at time of bidding and to estimate the cost of the operation after the change. The two models give an accurate picture of the direct costs involved the additional costs incurred due to the added complexity resulting from the change. The paper reviews the complexity claim, discusses the operation that is the subject of the dispute, and presents the CYCLONE models developed to assist in the mediation.

This paper describes a research project sponsored by an industrial partner to design a system that automates the process of acquiring field construction data. A survey of field supervisors revealed that the two field functions that require the most paperwork time are employee timekeeping and material management functions. Timekeeping functions required anywhere from 10–15%, and material management functions required 26–37% of a field supervisor's time. This system is desperately needed to solve the impending paper burden encountered on construction projects by field personnel, and should be utilized at the project level to provide significant time savings for field supervisory personnel. The automation device chosen for this project was a pen‐based portable computer. Field applications were developed and demonstrated in the field at two job sites to determine user reaction and input. Results from these two demonstrations indicate that this type of hardware device possesses the potential and capability to automate construction field‐data collection. These two applications are described in the paper along with a review of commercially available software and hardware.

This paper describes a computerized approach for collecting and processing site information that builds on the traditional superintendent's daily site report. System design considerations and features, lessons learned from field use, and future extensions are highlighted. Goals include improvements in the ease and accuracy with which field data can be recorded and processed to produce fast feedback on project status and problems. Benefits claimed for the approach include development of a coherent picture of the current status of a project and how it got there; faster response time in dealing with problems; integration of the site reporting, project planning, and project scheduling functions; an increased likelihood of schedule updating and speedier updating (thus leading to increased schedule credibility); help in dealing with claims; and documentation of experience in a form useful for future projects.

A fully implemented and active system of microcomputer support at the jobsite came into being from a long‐felt need on the owner's part to have better control over the status of shop‐drawing submittals, change orders, material flow, requests for information, and the administrative status of subcontractors and suppliers. In addition, there was clearly a need for more integration of financial and accounting information with recorded job status both at the jobsite and in the home office. Some half‐dozen years in development, the system described herein relies on custom‐designed proprietary programs to facilitate handling of the construction unique activities and management monitoring requirements. Jobsite hardware is standard PCs with monitors and simple dot matrix printers. An operational description begins at the jobsite where project managers have a constant need to process and monitor the development of data generated by the unfolding of project activity. The ability to access the resulting information in a more timely and comprehensive manner enhances the project manager's leverage to implement more effective control. The system is operational and used enthusiastically by all players in the process. Configurations are described with interactions and transfer functions.