Flexible domain viewer for supporting multi-trade views of three-dimensional CAD data

In response to the need for allowing electronic design data to be reused directly in construction management applications, many CAD developers for the AEC industry have started implementing a semantic data model in their CAD products using industry foundation classes (IFCs). While helpful, these semantic CAD applications have limitations when used in actual construction practices. The case studies in the thesis indicated that: (1) the semantics of the current data model (IFC as an example) is not rich enough to cover the richer details of the real trade practices; (2) the current implementation of the semantic data model lacks a mechanism to provide multiple trades views at various detailed levels.;The main difficulty in developing a single data model to represent perspectives from all AEC trades is due to the fact that there are many different construction methods and products and each construction method will have its own domain-specific views to the data model. Developing such a single data model is very unrealistic if not impossible.;An alternate approach to a single AEC data model is to allow users to define their own domain specific views based on the core CAD dataset. This approach should allow the users to add their own domain-specific knowledge. Another advantage of this approach is that it will keep the data model simple because the trade specific knowledge is not part of the CAD data model. Instead the trade-specific knowledge is a self-contained extension of the CAD data model.;The objective of this dissertation is to develop a flexible mechanism to allow the domain users to generate their own views using the shared 3DCAD data set. The challenge of this research lies in how to design such a mechanism, which is flexible enough to generate multiple domain views based on the shared 3D CAD data set while being more efficient than the manual quantity takeoff.;This research proposes the concept of a flexible domain viewer, which is a user interface and which allows the users to use their existing domain knowledge and experience and apply them semi-automatically to the corresponding design component in 3D CAD. A prototype of the concepts using IFC data is implemented to do quick cost estimates for multiple trades using the same 3D CAD data. As proof of concept, the multi-domain capability of the proposed approach was tested on three projects of different complexity levels. The results showed that the proposed system has clear advantages over the traditional manual estimating method and existing CAD estimating method.