OBJECT-ORIENTED PRODUCT MODELING FOR COMPUTER-INTEGRATED MANUFACTURING

Design representations currently used in CAD systems are inadequate for the full integration of CAD with planning and production systems used in automated manufacturing facilities. To facilitate this integration and adequately support engineering and managerial activities in computer-integrated manufacturing systems (CIMS), product design representation should satisfy at least the following requirements: information completeness, data and knowledge encapsulation, and data model accessibility. An object-oriented product model has therefore been developed to satisfy these requirements and provides for the design representation of a product. The model has a multi-level hierarchical structure incorporating the following six classes of objects: product, sub-assembly, part, CSGtree, solid primitive and feature. Each of these classes provides a particular set of information required by design and manufacturing. The product model has been implemented in Smalltalk as part of an integrated modelling system to support product modelling, solid modelling, and process planning for machining and inspection. Examples are included to demonstrate the features of the model and its applications in solid modelling and process planning.