Construction site layout is widely acknowledged to have a substantial impact on efficiency by affecting the travel time of workers, transportation of materials and equipment around a jobsite, and by its potential impact on workes safety. Yet formal design approaches for site layout exist only in a few specific sub-areas, e.g., crane selection. Publications which address the overall site layout problem tend to offer, at best, empirical guidelines for designing an efficient layout. Knowledge-based systems have achieved levels of performance comparable to that of human experts for problems of diagnosis or selection in several domains. However, expert systems for planning or design tasks are far more difficult to construct and have achieved only modest levels of performance to date. In addition to the generic challenges associated with developing expert systems for design tasks, an expert system for construction site layout raises a number of specific research issues including: integration of multiple knowledge sources,spacial reasoning and temporal reasoning. To address these issues, the BB1 blackboard architecture will be used. This was specifically designed to employ and mediate between multiple knowledge sources in expert systems, and which has been extended in an ongoing research project to address the problems of spatial reasoning. The proposed research has the potential to advance the practice of construction engineering, and to contribute to the development of expert systems for spatial layout in a number of domains.
