The purpose of this research is to develop a methodology and a prototype system that allows the integration of product design with manufacturing planning. The task is achieved through an integrated ...CAD-CAPP-CAFP$\sp1$ environment. The system consists of three major modules, namely, Feature Analyzer, Process Planner and Fixture Planner. The manufacturing information of a part required for process and fixture planning is extracted from the 3-D geometric model and the 2-D engineering drawing, thereby both geometric and non-geometric attributes of a part can be obtained. An integrated approach to process and fixture planning is adopted to ensure that the process plan for a part is generated on the basis of a workable fixture plan. The approaches to feature analysis and to integrating process and fixture planning are introduced. Fixture planning is an important part of CAPP, which is the link between design and manufacturing in a CIM$\sp2$ environment. We propose a rationalized approach to computer-assisted fixture planning (CAFP) with an emphasis on integration of fixture planning with process planning, an issue that has not been adequately addressed until very recently. A systematic approach to fixture classification and selection is outlined for the planning of modular fixtures. A prototype CAPP-CAFP system has been linked to a commercial CAD system, namely, CADAM. Part design information can be extracted from the CADAM system and the fixture assembly layout can be displayed on-screen. A routine fixture analysis based on both kinematics and the force equilibrium model is also included in the system for verification of a fixture design. The proposed force analysis model, which also takes into account friction force, determines the minimum clamping forces required to maintain the equilibrium of the workpiece during the process of machining. Through a simulation method, an iteration process will determine a feasible solution to the non-deterministic fixturing problem. ftn$\sp1$CAD, CAPP and CAFP are the abbreviations of computer-aided design, computer-assisted process planning, and computer-assisted fixture planning, respectively. $\sp2$CIM: Computer-Integrated Manufacturing.
