A design by features approach to the building of feature data models for process planning

As research and development in Computer Aided Design and Manufacture (CAD/CAM) progresses, the integration of activities such as design, analysis, process planning, assembly planning, production planning becomes ever more complex and important. It has been recognized that a feature based representation of parts is a key to solving this problem. Unfortunately, neither has a feature representation scheme (or standard) yet been generally accepted, nor has a CAD system successfully represented feature information. Ongoing research into process capability modelling is aimed at solving the above problems in the process planning domain. In this paper, a design by features system, which consists of a design by features user interface and an integrated Boundary Representation solid modeller, is introduced. A feature representation scheme that has been implemented in the system is also presented. Although the design by features approach still has limitations, it overcomes some severe problems with the alternative feature recognition approach, such as the complexity of the recognition process, the limited number of features that can be identified from the geometric representations of pans and the absence of the designer's intent.