Abstract

Axiomatic design (AD) is a well known design methodology in which the design activity consists of mapping between four domains, i.e. customer, functional, physical and process. According to AD theory only designs that satisfy the so called independence axiom are accepted, as they lead to uncoupled or decoupled designs. However, many engineering designs do include coupling terms of various degrees of strength. We propose an effective method of measuring the functional couplings’ effect on the product, so as to improve the whole design process. The method is based on fuzzy set theory -a valuable tool for dealing with imprecision and uncertainty of engineer judgement- in particular the Fuzzy Analytic Hierarchy Process in order to estimate the coupling terms’ weights. The effectiveness of the proposed method is demonstrated by an illustrative example. The required calculations are carried out by SoftFAHP, a software package developed by our laboratory for supporting both the typical and fuzzy AHP.