Extensible object-oriented computer-aided design system

This research focuses on the extensibility in an object-oriented Computer-Aided-Design (CAD) environment. By providing utility functions to edit class definition and class hierarchy, and to change instances from one class to another it is argued that the object representation of designed products can be extended or modified, during system usage, beyond the originally conceived scope of the CAD system, and thereby enhance the system's domain of application. A subset of structural design problem, namely single-story steel frame design, is chosen for the proof-of-concept research. A prototype system was built and evaluated to identify whether an extensible, object-oriented CAD system is a feasible and plausible approach to structural design. System testing and evaluation produced positive results on the questions of feasibility and plausibility. It is argued that with extensibility better intra- and inter-disciplinary integrations can be achieved. And recommendations on directions of future research are made in the final chapter.