CAD and the product master model

We develop an architecture for a product master model that federates CAD systems with downstream application processes for different feature views that are part of the design process. The architecture addresses especially the need to make persistent associations of design information with net shape elements. Moreover, the design respects the need of commercial CAD systems (and of downstream applications) to maintain proprietary information that must not be disclosed in the master model. Two case studies consider the requirements on the master model architecture for geometric dimensioning and tolerancing, and for manufacturing process planning using NC machining. We discuss how to reconcile the associated feature views and how to update them under net shape redesign. The case studies indicate that many design changes that arise from these downstream views can be formalized by a well-defined problem on dimensional and geometric constraints. (C) 1998 Elsevier Science Ltd. All rights reserved.