Metamodel: A key to intelligent CAD systems

We introduce the metamodel as a new modeling framework for design objects based on General Design Theory, a mathematical model of design. Using General Design Theory, the metamodel concept can serve three functions: (1) as a central modeling mechanism to integrate models, (2) as a mechanism for modeling physical phenomena, and (3) as a tool for describing evolving design objects. Modeling with multiple points of view is realized by representing physical phenomena that occur in the deisng object and by constructing models with knowledge of physics and design from the metamodel. We illustrate the first and second functions of metamodels with an example based on naive physics, and we illustrate the third function of the metamodel through design experiments. Finally, we present two systems to illustrate how the metamodel mechanism can be implemented.