Reiner Anderl The Advanced Modelling part of the CAD*I project aimed at the development of a new generation of modelling techniques as a basic functionality of future CAD/CAM systems. The methodology and concepts for advanced modelling techniques, their availability in the communication interface of a CAD/CAM system and their influence on internal interfaces in the software architecture of a CAD/CAM system are fundamental results of advanced modelling work. These results form the basis for the development of a new generation of CAD/CAM systems which are called product modelling systems. CAD/CAM systems today mainly support the geometric description of a technical part or its description as a technical drawing. Advanced geometric modelling capabilities deal with parametric design functions embedded into CAD/CAM systems. However, development strategies for future CAD/CAM systems are directed toward the following: 1. The development of product modelling systems and 2. the development of integrated systems based on CAD, CAP (Computer Aided Planning), CAM and other CIM (Computer Integrated Manu­ facturing) functionalities.