Journal of Construction Engineering and Management

This paper presents a comparison of labor productivity for masonry activities from seven countries. Case‐study projects were selected from Australia, Canada, England, Finland, Scotland, Sweden, and the United States. Productivity data were collected by participating researchers using a procedures manual detailing how data were to be collected. Standardized data from 13 projects were assembled into a data base consisting of 465 days or records. Statistical analyses indicated little difference in the productivity from the seven countries despite significant differences in labor practices. The principal difference was the management influence. The more disruptions, the worse the productivity. This project marks the first reported effort to collect productivity in a standardized manner from multiple projects on the international level. Differences in productivity for this work were exaggerated.

The construction project planning (CPP) stage is a critical stage in the project development and delivery phase of the life cycle of a building project. This stage lays the framework upon which most of the construction decisions are made. Despite its importance, many construction firms go through this stage in an arbitrary fashion. This problem is particularly crucial for small‐medium‐size building projects and the firms constructing such projects in a design‐build environment. The CPP stage for such firms is chosen as the targeted domain of construction for this paper. The research effort reported in this paper had the following objectives: (1) To highlight the importance of CPP as an integral function of the construction project management cycle; and (2) to develop a CPP process model that can provide descriptive representation of the microlevel steps of an integrated approach to cost plans and time plans generation. The usefulness of such a model to serve a number of needs related to project planning, is demonstrated by associating each step of the CPP process with the appropriate conventional or knowledge‐based computer applications.

Properly applied financial incentives are a powerful motivational tool that can inspire employees to improve their performance, thus increasing profits and strengthening the company. In light of such potential benefits it is unfortunate that the overwhelming majority of construction contractors do not offer financial incentives to their field workers. Research is performed to study many issues relating to financial incentive programs for small‐to‐medium‐size construction companies located in the southeastern United States. The results of the study indicate that the contractors surveyed generally knew about financial incentive programs, used different types of them to increase productivity, rarely studied financial incentive programs, needed firm proof that programs are effective and efficient, and desired information on how to develop one for their own company. If a financial incentive program is to be developed it must have commitment from top management, be based on realistic productivity standards, be efficiently managed, and have worker support.

In the development of a project, a significant role is played initially by the designer of the project and then by the constructor of the project. Construction worker safety has often been regarded the sole responsibility of the construction contractor. Despite the obvious reasons for placing the primary responsibility on the contractor, the safety performance on a project may well be dictated to a large extent by decisions made by the designer. To investigate this issue of whether designers were sensitive to the safety of construction workers, a survey of major U.S. design firms was conducted assessing the extent to which design decisions are made with specific consideration being given to the safety of construction workers. Of the respondents, only one‐third stated that they made design decisions with the specific intent of improving safety conditions for construction workers. Specific illustrations of such design decisions are given in the paper. The fear of increased litigation is the biggest deterrent to addressing construction worker safety in design decisions. A rationale is developed in the paper for supporting the thesis that designers should consider worker safety in their designs. Suggestions are offered on how construction worker safety might be addressed by more designers.

The time required to perform a given process in a repetitive construction environment tends to fall progressively as the same process is repeated for a sufficient number of successions. This paper discusses the aspects and fundamentals of learning development and its impact on the time requirement of repetitive construction processes from a simulation perspective. Common learning curves and their basic parameters and equations are highlighted. Factors that determine the level of learning rates for construction tasks are also investigated. We also introduce a statistically based approach for modeling learning development. Modeling learning phenomena in a simulation experiment is then introduced as applied in MicroCYCLONE (Halpin 1990). An example application is presented reflecting the impact of learning on the time requirement on a high‐rise building; the statistically based approach is compared to the currently used deterministric models. This paper presents a simulation‐based methodology for incorporating learning development in process simulation modeling and experimentation. In particular, it is suggested that a stochastic learning model be adopted due to the random factors affecting learning in construction. The paper highlights mathematical models often applied in modeling learning development and reviews the factors that contribute to these phenomena. An example application is also presented to illustrate how learning models can be incorporated into a simulation experiment. The effect of learning on the time required to complete a given process, and the significance of using stochastic versus deterministic learning models on various performance measures are also discussed.

This paper defines information requirements to support decision‐making needs of site‐level personnel constructing a facility. It focuses on information required to drive the process, rather than technical information for design‐related problems. The site‐level construction information system (SCIS) builds upon basic decision‐making theory and a common understanding of the construction process, as represented by the conceptual construction process model. SCIS consists of a four‐step process: (1) Establish a matrix of the key project decisions; (2) define the project control system for the given project; (3) establish methods to select the decision‐making mechanism, collect information, and implement decision; and (4) propose a method for monitoring the site information system. A case study illustrates key components of this method. A strategy for implementation then follows. The information model presented allows for information gathered from the formal project control system, informal information communication, and unstructured observations on site, to be integrated into a site‐level construction information system.

This paper suggests a new approach to the problem of providing computerized assistance in settling construction contract claims. Previous research on this topic has concentrated on the use of expert systems to try to predict the outcome of a claim, but has met with limited success. The proposed approach is to use a hypertext information system to assist in the analysis of a claim by informing contractors, owners, and their representatives of the contract provisions. The system does this by providing a precise hypertext guide to the contract wording, which is in turn linked to the relevant sections of various reference texts and descriptions of cases in which similar issues were determined. Careful structuring and linking of the data contained in the system are necessary to enable users to focus quickly on only relevant material. In this way, the system presents the users with the information they need in order for them to reach an informed decision on the validity of a claim.

This paper addresses the effective use of various levels of automation in concrete slab‐on‐grade construction, considering conventional manual construction, semiautomated placing using a laser‐guided screeding machine and automated finishing using a robotic floor finisher. For both manual construction and semiautomated placing, information is obtained through structured interviews of concrete contractors and site observations. Information on robotic finishing is obtained from robot developers. When compared to the conventional manual construction of a typical $1\text{,}859‐m^2\text{,}$ 150‐mm‐thick slab, accomplished in 10 hours with a 12‐man placing crew and a six‐man finishing crew, automation of finishing alone is found to offer benefits through a 30% reduction in the size of the finishing crew, whereas automation of placing alone offers benefits through a 33% reduction in the placing crew size and a 20% activity‐duration reduction. Automation of both placing and finishing allows a 33% placing‐crew‐reduction, 25% finishing‐crew increase, and a 60% activity‐duration reduction. These benefits are considerably increased when higher quality is explicitly specified.

A model that uses artificial intelligence programming techniques is presented as a new tool for layout designers. This model, named SightPlan, represents the layout process as well as the layout product. A description of the knowledge and problem‐solving method is given of the SightPlan system that mimics the actions of a human layout designer. SightPlan lays out temporary facilities, represented as rectangles, on a construction site, represented as a two‐dimensional space. An early‐commitment strategy and spatial constraint satisfaction techniques are used to find unique positions for facilities among those already in place. An example run in which SightPlan is applied to a case‐study project illustrates how the program operates in stand‐alone mode. SightPlan demonstrates that knowledge‐based systems can successfully address problems not adequately modeled until now and, thus, opens up a new way of thinking about computer‐aided decision support for the construction industry. The present system is a prototype, however. Additional work must be done before SightPlan will be ready for field use and useful to field practitioners.

This paper describes the important aspects of construction law that relate to differing‐site‐condition (DSC) disputes and presents a guide for contractors and contract administrators to resolve contract disputes based on the DSC contract clause. Based on research of more than 75 appellate decisions, the paper summarizes the remarkable consistency in case law decisions. Careful examination reveals that courts follow consistent patterns of inquiry. These patterns have been defined in an easy‐to‐follow flowchart describing the particular inquiry. A narrative containing numerous case citations and synopses accompanies each inquiry. An example, based on an actual case, is included to illustrate the use of the flowchart. The flowchart was tested using 10 other cases, and the outcome using the flowchart was the same as the judicial decision in each instance.

The construction industry, like any other, suffers great losses from substance abuse by employees. These losses include increased accidents, reduced physical and mental productivity, and increased medical expenses. These expenses are a burden on everyone's shoulders, the guilty as well as the innocent. Drug testing, which includes job‐applicant screening and testing of current employees, has generated much controversy, both technical and legal. The present study investigates the technical aspect of drug testing in the construction industry: Is it effective in reducing injury incident rates? Although incident rates for the whole sample dropped from 11.21 incidents per 200,000 man‐hours to 9.07 after drug testing, a 19% reduction, the difference was not proven statistically significant. The sample was broken down by company size, type (union, nonunion, or both), incident rate before testing, and other criteria. Two groups showed significant decreases in incident rates after testing: Companies that did not have a recent significant size increase, and companies with an incident rate above the national average that started a testing policy. Size, type, and number of drug testing types were not proven as factors influencing the change in incident rate.

This paper discusses items that can aid owners in predicting the chance of construction contractor failure prior to contract award and thus assist them in the evaluation process. A predictive contractor failure model has been developed and is discussed. The model predicts the probability of contractor failure at the project level; failure is defined as a significant breach of the contractor's legal reponsibilities to the owner (for example, bankruptcy or material breach of contract related to meeting desired project objectives such as cost, schedule, and quality). Data for the model development were collected using two questionnare surveys. The modeling method involves the use of discrete choice logistic regression. Results show that four variables are strong predictors of contractor failure: (1) The amount of owner‐contractor evaluation; (2) whether cost monitoring was performed by the owner; (3) the level of support received by the project manager from the contractor's senior management throughout the course of the project; and (4) the early involvement of the contractor's project manager. The model was validated using an additional 36 projects.

Every project owner is faced with the contract administration decision of what evaluation method to select to adequately establish and ensure the qualification of candidate construction contractors. The evaluation methods available include (1) owner-contractor prequalification, (2) surety bonding, or (3) owner-contractor prequalification along with surety bonding. This paper describes an investigation into these evaluation methods and their impact on project outcome: (1) failure or (2) nonfailure. Failure is defined in this study as a significant breach of the contractor's legal responsibilities to the owner (for example, bankruptcy or material breach of contract related to meeting desired project objectives such as cost, schedule, and quality). Data were collected using a questionnaire survey and personal interviews. With regard to the questionnaire survey, 85 different organizations responsed and provided a total of 120 projects; 47 involved a contractor failure. Twenty industry experts provided probabilities associated with the various project outcomes. Expected value theory is used to determine _expected outcomes of relevant project performance parameters. Results demonstrate that _better owner-contractor evaluation leads to enhanced project performance.