The Perspective Approach

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Abstract Architecture, engineering and construction (AEC) projects today are very complex, and require the expertise of hundreds, and sometimes thousands of engineers. Each of these engineers has task-specific expertise; hence they conceptualize the project in ways that are suited to their specific tasks. To help them perform these design, planning and execution tasks, they construct task-specific views of the project. The work of an engineer often impacts the work of other engineers; therefore these views must somehow be integrated as the project unfolds through time. In current practice constructing and integrating task-specific views is often time-consuming error-prone, and difficult. Ideally, engineers could automatically construct and integrate task-specific views. Many current project-modeling approaches construct and integrate a predefined central model from which task-specific views are automatically constructed. Others construct and integrate a “federation” of predefined task-specific views. AEC projects have been slow to adopt these approaches. This thesis presents industry test cases that illustrate that, because of the multi-disciplinary, constructive, iterative, and unique character of AEC projects, central approaches are difficult to implement. These test cases show that, to perform their tasks on these projects, AEC engineers construct task-specific engineering views from information in other engineers’ views. The test cases also show that it is difficult to predetermine the content of these views. Based on these observations, this thesis proposes that engineers could benefit from an approach that provides them with generic and simple, yet formal ways to represent a view, its dependencies on and relationships to other views, and to control the integration of these views as the project progresses. A project model emerges as a directed acyclic graph of task-specific views and dependencies. The thesis develops requirements for such an approach, and discusses that, while points of departure, existing project modeling approaches are not explicitly formalized to enable engineers to work in this way. To satisfy the requirements, this thesis formalizes the Perspective Approach. The Perspective Approach enables an engineer to construct a task-specific dependent engineering view, called a Perspective, by formalizing the existence, status, and nature of its dependency on source Perspectives. Engineers use composable, subsumable, modifiable reasoning modules, called Perspectors, to specify the nature of the dependency. Engineers can compose Perspectives and Perspectors into directed acyclic graph structures that specify complex transformations of source Perspectives into a dependent Perspective. The Perspective Approach also formalizes simple Management Processes that assist engineers to iteratively construct Perspectives, and control the integration of Perspectives with respect to the Perspectives on which they depend. A Project Model emerges as a directed acyclic graph of task-specific Perspectives and dependencies between Perspectives. The thesis focuses on the construction and integration of geometric views, because geometry is a common language of communication and coordination on AEC projects, although in principle the Perspective Approach could be used to construct and integrate other types of views. To validate the Perspective Approach, this thesis describes a prototype, called Perspector App, and retrospectively implements two test cases from the design and construction of the Walt Disney Concert Hall. The validation shows how the Perspective Approach could enable engineers to automatically construct and control the integration of these views more quickly, accurately and completely than possible on this state of the art project. The validation automates the design of metal deck attachments that are required to connect concrete slabs to steel beams, and automates the analysis of cantilever conditions between architectural ceiling panels and the steel hangers that support them. The validation also shows that several of the Perspectors were reused in both test cases: it may be possible to define a small number of reusable Perspectors, potentially a language, which engineers can learn to use. The Perspective Approach is designed to be a general, yet powerful framework in which engineers from multiple disciplines can quickly yet formally construct and integrate task-specific views from other engineering views. It is intended to enable engineers to engage in automated, integrated design and analysis. Click Here for the Introduction