| In the traditional process of product design, a sequential and ad hoc approach treats each of the design steps in an isolated mode. The knowledge of design engineers about manufacturing and assembly processes is often the key to a good design. The lack of a systematic and simultaneous consideration of the impact of design decisions on manufacturing and assembly leads to repeated and excessive changes in design and processes. To resolve this problem, the concurrent engineering approach to product design foresees and eliminates potential design flaws by integrating design information throughout the product development life cycle early in the design stage.;This research presents a product life cycle design framework in the context of concurrent engineering. The integration of design information is realized by feature-based and object-oriented part representation. Through a unified organization of semantics of high level design features and relationships, this representation provides a mechanism to evaluate the impact of design on subsequent activities in the product life cycle, such as Design for Manufacture (DFM), Design for Assembly (DFA) and Design for Productivity (DFP). In addition to making selections of design candidates based on multiple design criteria, it is also capable of handling the imprecision of design information and user preferences by multi-objective utility theory. A Genetic Algorithm based parametric optimization further fine tunes the design parameters. An illustrative example of two real designs of a milling fixture demonstrates the effectiveness of the framework and its implementation. |
