Perspectors: composable, reusable reasoning modules to construct an engineering view from other engineering views John Haymaker * , John Kunz, Ben Suter, Martin Fischer Department of Civil and Environmental Engineering, Center for Integrated Facility Engineering, Stanford University, Building 550, Room 553H, Stanford, CA 94305-4020, USA Received 23 December 2003; revised 4 October 2004; accepted 4 October 2004 Abstract As engineers design, plan, and execute architecture, engineering, and construction (AEC) projects, they construct task-specific views. These views contain information that is structured for their specific tasks. Engineers generally construct these views based on information contained in other engineers’ views. Traditionally, engineers have manually constructed these views using pencils and more recently with computational tools like computer-aided drafting (CAD). Manually constructing and integrating views is often difficult, time-consuming, and error-prone. Newer project model approaches attempt to predetermine and automatically construct many useful task-specific views but these approaches are proving difficult to implement due to the multidisciplinary, constructive, iterative, and unique character of AEC projects. Current project modeling approaches lack adequately simple, formal, generic, expressive methods that engineers can use to automatically construct a new dependent view from information in one or many source views. In this paper, we formalize reusable reasoning modules, called Perspectors, which engineers can use to automatically construct a task-specific engineering view, called a Perspective, from other Perspectives. We motivate and retrospectively validate this approach using engineering test cases from the design and construction of the Walt Disney Concert Hall. Through implementation of a prototype, we give empirical evidence that engineers can select from a potentially small number of pre-defined, reusable, geometric Perspectors, or program new Perspectors, and easily compose them into directed graph structures, called Narratives, to construct and control the integration of useful dependent geometric Perspectives more quickly and accurately than current practice and theory allows. Perspectors are intended to enable engineers from multiple disciplines to engage in novel, automated, and integrated design and analysis by easily yet formally constructing and integrating Perspectives from other Perspectives. q 2004 Published by Elsevier Ltd. Keywords: Building information modeling; Product models; Process models; Organization models; Collaborative design; Design automation; Geometric reasoning; Perspectives; Perspectors; Narratives 1. Introduction Engineers construct engineering representations, or views, as they perform-specific design, planning, and project execution tasks. Within these views, they construct features that are ideally structured for their specific task. They often construct and integrate these views from information in other engineering views created in earlier design, planning, and project execution stages (see Fig. 1A). The first author spent 6 months working with the engineers on the Walt Disney Concert Hall (WDCH) project and observing the state-of-the-art use of information technology on an AEC project of very high complexity. This paper reviews test cases from the WDCH that were detailed in Haymaker et al. [24]. The test cases illustrate: (1) the multidisciplinary, constructive, iterative, and unique nature of AEC projects; (2) that engineers on these projects need to construct and integrate task-specific geometric engineering views; (3) that engineers construct and integrate such views 1474-0346/$ - see front matter q 2004 Published by Elsevier Ltd. doi:10.1016/j.aei.2004.10.002 Advanced Engineering Informatics 18 (2004) 49–67 www.elsevier.com/locate/aei * Corresponding author. Tel.: C1 650 723 4945; fax: C1 650 723 4806. E-mail addresses: haymaker@stanford.edu (J. Haymaker), kunz@ stanford.edu (J. Kunz), bsuter@stanford.edu (B. Suter), fischer@stanford.edu (M. Fischer).