Copyright notice: This paper has been published in: Lindemann, U. ; Birkhofer, H. ; Meerkamm, H. ; Vajna, S. (Eds.): Proceedings of the 12th International Conference on Engineering Design : ICED 99. Volume 3. Garching : Technische Universität München. 1999. - Munich Germany, August 24-26, 1999. - ISBN 3-922979-53-X, pp. 1593-1598. As a courtesy to the publisher, this paper may not be reproduced or distributed in any form. 3INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN ICED 99 MUNICH, AUGUST 24-26, 1999 A SHARED KNOWLEDGE BASE FOR INTERDISCIPLINARY PARAMETRIC PRODUCT DATA MODELS IN CAD Dirk Schäfer, Oliver Eck, Dieter Roller Keywords: Knowledge-based CAD, Shared Design Databases, Parametric and Constraint Product Modeling, Constraint Propagation, Simultaneous Engineering 1 Introduction Practicing Simultaneous Engineering, companies parallelize product design in several design processes. Hereby, interdisciplinary and geographically distributed teams have to cooperate closely to make the overall design process - called Interdisciplinary Global Engineering Process - efficient. Although these teams often work on different parts, dependencies between their models have to be considered. Interdisciplinary dependencies between CAD models of different domains such as mechanical and electrical engineering usually can not be modeled in single proprietary CAD systems. An appropriate solution is to model, evaluate, and propagate them in a shared distributed knowledge base. To reach this aim, extensions of parametric and constraint-based modeling concepts are required. Whenever automatic constraint propagation is not possible because of the dependency complexity, the knowledge base provides an automatic user notification as a constraint propagation mechanism. 2 IGEP In order to remain competitive in the global market, companies are forced to find new and more efficient CAE concepts for improving their overall process from design to manufacture. In future, companies have to organize their product design using several parallel design processes to be performed by interdisciplinary and geographically distributed teams. These teams have to cooperate closely to make the overall design process - which is called Interdisciplinary Global Engineering Process (IGEP) - efficient. In the past, three major philosophies have been followed to realize Simultaneous Engineering. Lean management and workflow management have proven their potential to improve the in- house strategies. On the other hand, in respect to manufacturing processes, Outsourcing became to be the most commonly used approach. Another important state of the art technique to make design processes more efficient, that furthermore improves the overall design quality, has been developed during the last decade: Parametric modeling. Unfortunately, today this approach to variational design is available only for mechanical engineering CAD environments (MCAD). However, a lot of research is