Journal of Construction Engineering and Management

While tower cranes traditionally are identified with high-rise, congested urban building construction, and mobile cranes primarily are associated with heavy civil and infrastructure construction, there exists a vast population of building projects where both are feasible. The question, then, is: why are different crane types used under similar project conditions in different geographic areas (e.g., tower cranes in Europe, mobile cranes in the United States)? This paper examines the culture of using mobile cranes for building construction, as observed in the southwestern United States. Project-specific and environmental characteristics are identified, classified, and described, while comparatively relating to tower crane practice. The role of non–project-specific factors (such as planning culture, operating style, employment patterns, and market organization) is emphasized in shaping the mobile crane culture. A rather homogeneous population of projects with distinct features, such as short construction duration, spacious sites, and supportive terrain, creates the grounds for this culture's evolution. Understanding the relationships between and within project and environmental characteristics is vital for a construction market that is becoming global and for a fresh examination of traditional equipment selection practices.

Estimating the durations of construction activities requires experts knowledge. Statements used by these experts usually contain some sort of imprecision. Previous studies have demonstrated the use of fuzzy set theory for quantifying the imprecision associated with the durations of project activities. These studies, however, did not address the processing of this information for generating a complete schedule. This paper presents a new network scheduling method based on fuzzy sets theory. The proposed method incorporates a number of new techniques that facilitate: (1) the representation of imprecise activity durations; (2) the calculation of scheduling parameters; and (3) the interpretation of the fuzzy results generated. Two network examples are worked out to illustrate the use of the proposed method, and to compare its capabilities with Monte Carlo simulation. The results indicate that the proposed method is capable of providing schedules that can appropriately account for the nature as well as the type of uncertainties normally encountered in construction projects. The results are in close agreement with those obtained using Monte Carlo simulation. The calculations are, however, more simple, requiring less computational effort than that needed in Monte Carlo simulation. The proposed method is practical and can be easily computerized.

The Build-Operate-Transfer (BOT) concept has now become an accepted means of securing private-sector involvement in infrastructure projects. The popularity of BOT mechanisms is growing in the developing countries, which offers increasing investment, construction, procurement, and other business opportunities for the investors from developed countries. This paper identifies the major areas where BOT systems are applied in China. Market potential for absorbing foreign investment involved in a BOT system has been evaluated. In particular, the market prospects for power, transportation, and water resource projects are investigated. The study also identifies the enjoyable benefits, other favorable conditions, and key factors affecting the application of BOT in the Chinese infrastructure projects. The government policies on taxation, foreign exchange, and favorable conditions to attract foreign investment to this application are examined. The applicable investment patterns and the procedures of adopting BOT have been investigated, and are presented to assist foreign investors planning to develop infrastructure projects in China.

The use of value engineering in the United States of America has grown significantly in the last twenty years. Advocates of the system claim it is effective in reducing cost and improving the value of construction projects. Others however claim that in reality the technique is little more than traditional cost cutting by another name. This paper makes a holistic appraisal of value engineering as used in the United States of America's construction industry by investigating current theory and practice. It evaluates value engineering projects and calculates the savings achieved by them. It goes on to analyze the nature of those savings. It looks at four VE workshops and makes an appraisal of the technique. Finally it draws overall conclusions about the current position of value engineering in the United States of America.

This study develops an automated site layout system for construction temporary facilities (TFs). The system, ArcSite, including a geographic information system (GIS) integrated with database management systems (DBMSs) is a new tool to assist designers in identifying suitable areas to locate TFs. ArcSite consists of knowledge specific to construction site layout, TF databases, Arc/Info databases, and algorithms for integrating and automating TF layout design. The system proposes a method, the knowledge acquisition form, to systematically acquire and interpret experts' knowledge and experience in site planning. Using the concept of searching by elimination, the system develops a heuristic approach to model the process of human decision-making and generate the potential sites for each TF. Through both qualitative and quantitative modeling of facility relationships, an objective function called proximity index is developed to determine the optimal site of each TF. ArcSite demonstrates that GIS is a promising tool for solving construction layout problems and, thus, opens up a new way of thinking in the management of spatial information for construction planning and design.

Current scheduling tools require the manual translation of design information to activities and typically do not provide dynamic links between cost estimates and corresponding schedules. To take advantage of the increasingly electronic and object-based descriptions of designs, schedules, and estimates, integration mechanisms that translate design descriptions into schedule and cost views of projects are needed. This paper presents computer-interpretable models for the representation of construction methods as one such a mechanism. These models support the automated generation of realistic construction schedules. Methods elaborate higher-level activities into appropriate lower-level activities to link schedules of various levels of detail. Five attributes define a construction method: domain, constituting activities, activity sequencing, constituting objects, and resource requirements. These construction method models can act as templates to capture production and scheduling knowledge specific to firms and projects. We illustrate the use and implementation of these models by scheduling the construction of a small masonry structure. These models assist architects, owners, and contractors in studying cost and schedule implications of design and construction alternatives.

Contaminated site remediation projects have characteristics that distinguish them from conventional construction projects, including substantial regulatory oversight and significant uncertainty about subsurface conditions and the effectiveness of the remedial technology chosen. The unusual features of remediation projects suggests that nontraditional or innovative contracting mechanisms may be beneficial. Sixty completed remediation projects were studied to identify and document the effects of different project management structures and contracting strategies on project outcomes. Survey results indicated that changes in scope, budget overruns, delays, disputes, and change orders are common on remediation projects. Flexible project management strategies, such as turnkey and partnering arrangements, and flexible contracting schemes, such as cost plus fee, were found to be better suited to accommodate such changes. Turnkey and design/construct project structures had the best performance overall of the management structures reported. Mechanisms to promote partnering and team building contributed significantly to project success as defined by budget and schedule.

Heavy lift planning has a major impact on construction sequencing, scheduling, budgeting, and safety. This paper addresses problems presented by planning for multiple lifts on a single jobsite. This is a common and particularly challenging planning situation because of the complex trade-offs involved. Conventional intuitive planning procedures lead to suboptimal plans or plans ranked with little quantitative or objective measure. This paper first introduces various factors affecting planning decisions for multiple heavy lifts and then presents an interactive computer-aided process to optimize initial crane configurations and placement locations for multiple lift problems. In the computer-aided planning process, the minimal number of equipment relocations is determined based on an integer programming model, and the precise equipment locations are optimized with an interactive procedure using objective performance functions. Objectives involve cost, safety, and area interference (area sterilization). These optimization procedures are implemented in the critical operations planning environment (COPE). A case study is used to demonstrate the optimization process. It is concluded, based on a case study and external reviews, that the process and algorithms presented help produce good plans for multiple heavy lifts on construction sites.

The short-term task scheduling of electrical foremen working in commercial and institutional construction projects was evaluated using a combination of interviews, questionnaires, and field observations. The planning environment was evaluated qualitatively, including the project and firm size, availability of resources, planning horizon, and issuing of directives. The quantitative analysis of factors presumed to affect the scheduling was emphasized in the investigation. These factors included task duration, criticality, likelihood of problems during execution, actual problems, and offset in planned start. This investigation found that foremen had almost complete authority over their daily crew task assignments. The favored planning span to articulate an explicit schedule was the workweek. Labor availability was more constraining than material supply in the formulation of the schedule. Directives were verbally issued in all observed cases. Analysis of scheduling parameters showed that dependence on other subcontractors' progress was the most common source of problems, and that problems acted as uniform background noise in the scheduling accuracy. Short and near tasks were the easiest to schedule. Some tasks were categorized as “fillers,” used to achieve continuity in labor utilization.