Functional case modelling for knowledge-driven conceptual design

Abstract

Traditional case modelling is focused on design configuration within product family for entire product reuse, while functional modelling provides a cross-domain function basis, which is much needed in concept generation. In this paper, we propose a combined approach; that is, functional case modelling for design concept alternatives. Functionality, structural information, and case attributes are integrated into functional case modelling. In particular, functional case attributes are derived from behavioural and environmental performances, which are different from traditional case modelling. Conceptual design aid is performed with two procedures in this framework. First, functional reasoning (FR) is employed for case clustering based on functionality. A case family is generated, the members of which are cross-product or even cross-domain families, and have similar functions with a required function. Second, constrained similarity measurement (CSM) is used for case selection from the case family, which is generated by FR. The CSM takes design constraints into consideration for design problem solving, which makes the case selection more reasonable. A prototype system named a functional case design support system is developed based on this framework, and a case study is presented to demonstrate this approach.