Version Modeling concepts for Computer-Aided Design Databases

We describe a semantic object-oriented data model for representing how a complex design database evolves over time. Structural relationships, introduced by the data management system, are imposed on the objects created by existing CAD tools. The relationships supported by the model are (1) version histories, (2) time-varying configurations, and (3) equivalences among objects of different types. We describe mechanisms for (1) identifying current versions, (2) supporting dynamic configuration binding, and (3) verifying equivalence relationships. The data model is being implemented in a Version Server, under development at the University of California, Berkeley