SYNTHESIS OF DESIGN CONCEPTS FROM A DESIGN FOR ASSEMBLY PERSPECTIVE

Assembly is often a labor intensive and costly process, Techniques suc h as design for assembly, and automatic assembly planning have been re ported in an attempt to lower the high cost of assembly. Automatic ass embly planning is concerned with finding the optimal sequence of assem bly for a given design. On the other hand, design for assembly (DFA) e xamines the given design to evaluate its 'fitness' for assembly, and w here appropriate, to provide high-level suggestions to redesign the co mponents so that they are easy to be assembled. Usually, DFA analysis is performed only when the design details are known (the number, types , and shapes of components and their mating relationships). As a resul t, designers tend to view this as an extra step/burden. To change this perspective, we investigate a new approach whereby DFA analysis is us ed to guide the designer in the search for a 'good' initial design. In this paper, we propose an architecture that incorporates design for a ssembly analysis into the conceptual design phase. With this incorpora tion, timely suggestions are made available to guide the designer in h is/her search for a feasible assembly-oriented design. A system has be en developed (in the National University of Singapore) to realize this architecture. The system is written in C using the Pro/Engineer platf orm. the system takes, as input, a description of the product's functi onal requirements in the form of a state transition diagram. A library of past design cases in the domain of chairs has been created. A simp le example of chair redesign has been presented to demonstrate the fea sibility of the proposed scheme. (C) 1998 Elsevier Science Ltd. All ri ghts reserved