TradeOff Strategies in Engineering Design（在工程设计折衷策略）.pdf

Trade-Off Strategies in Engineering Design Kevin N. Otto Erik K. Antonsson Engineering Design Research Laboratory Division of Engineering and Applied Science California Institute of Technology January 8, 1991 Abstract A formal method to allow designers to explicitly make trade-off decisions is presented. The methodology can be used when an engineer wishes to rate the design by the weakest aspect, or by cooperatively considering the overall performance, or a combination of these strategies. The design problem is formulated with preference rankings, similar to a utility theory or fuzzy sets approach. This approach separates the design trade-off strategy from the performance expressions. The details of the mathematical formulation are presented and discussed, along with two design examples: one from the preliminary design domain, and one from the parameter design domain. 1 Introduction For a robust automation, design decision making methods need to be advanced to represent and manipulate a design’s different concerns and uncertainties. This development is crucial, since the preliminary decision making process of any design cycle has the greatest effect on overall cost [3, 6, 14]. In a design decision making process, engineers must trade-off widely differing concepts to realize a result which maximizes their overall preference for a design. These concepts are usually incommensurate: for example, they could be as different as cost, degree of safety, degree of manufacturability, or amount of various perfor