Towards Redesign of Manufacturing Processes based on Functional Understanding

Functionality plays an important role in design problems, because it represents a part of “design rationales” [Chandarasekaran et al. 93, Lee 97]. A lot of research has been carried out on functional representation of artifacts such as [Chandrasekaran et al. 93, Iwasaki et al. 93, Lind 94, Sasajima et al. 95]. Many of them investigate only “to achieve”-type relations among functions. Nevertheless, types of relations among functions are not only the “to achieve” but also others such as “to prevent” and “to allow”. For example, an inspection process P allows a previous process Pp to produce defective objects, and prevents them from flowing into a next process Pn. The former contributes to simplifying the equipment of Pp and hence to saving of costs. The later prevents misbehavior of Pn. We call such dependency among functions a relational function.