Towards an optimal degree of design coupling through fuzzy analysis

It has long been recognized that we need some fundamental, correct principl es and methodologies to guide decision making in design. One important deci sion to be made in design is the determination of the optimal degree of des ign coupling among the components. Two components are physically coupled to gether if the design features of both components have been integrated to fo rm one single physical component. This ability to decide on the optimal deg ree of design coupling has a direct impact on the number of components in t he final design which, in turns, affects the maintainability, assemblabilit y, testability, and adaptability of the resultant product. Design for assem bly guidelines tell us to reduce the number of components in the final desi gn. This implies that we should, as far as possible, strive for the highest degree of physical integration of parts. This may prove to be too simplist ic a guideline. In this paper, we attempt to show that there exist circumst ances where design coupling is undesirable. We then propose a systematic ap proach for determining the optimal degree of design coupling among the comp onents.