General information model for representing machining features in CAPP systems

Today, the generality of computer-aided process planning (CAPP) systems and their standardization do not achieve satisfactory standards levels for industry. One of the major causes here is the difficulty of integration with computer-aided design applications, due mainly to the product model used. It is therefore necessary to identify models that are general with regard to the products, but at the same time suitable for CAPP. A product model suitable for CAPP must represent the product conceptually, enabling the development of process planning functions that operate with manufacturing concepts. It is therefore necessary to develop product information models using this philosophy. The present paper focuses on this problem and proposes an information system for representing the product for internal CAPP use. It is geared towards representing all of the part information (necessary for manufacturing) integrally with the machining features and under the same concept as these features. To this end, one of the main characteristics of the model is the absence of conventional geometric entities. The application domain of the model proposed is the assignment of processes and machines in machined parts. The GF-CAPP system has revealed that the advantages of using this type of product model in CAPP are its generality with regard to the product and the ease of developing functional procedures that are general, simple and independent.