The method for analysing and disposing of functional interaction in axiomatic design

Abstract

The ill-defined interactions among functional requirements (FRs) lead to additional iterations among tasks in the design process guided by axiomatic design. This article aims to develop a structured method for analysing and disposing of functional interactions in a coupled design so as to improve the design process. First, the representation of coupled FRs is given and the notion of a critical design parameter is introduced to assist the interaction analysis between FRs. Next, the identified coupled FRs are disposed of by decoupling. The decoupling condition for coupled FRs based on design specifications is given according to the interaction analysis. To enlarge the decoupling range, the concept of satisfaction degree is introduced and a coupled design may be decoupled based on the satisfaction degree. Then, for the remaining coupled FRs after decoupling, it is a good way to adopt tearing to find a better initial ordering of iteration for speeding up the convergence of iteration in terms of the interaction analysis. An index called quality loss is introduced to aid the reordering process. Finally, two practical examples are provided to illustrate the analysis and disposal process.