Independence Measure (IM) Using Independence Priority Number (IPN) in Axiomatic Design Framework

Abstract

Axiomatic Design is becoming a preferred system design process tool for insuring the quality and efficiency of design processes for products and services. One aspect of Axiomatic Design is modeling and analyzing the functional independence of proposed solutions. Axiomatic Design provides for comparing and ranking solutions by three categories of functional coupling: Uncoupled, Decoupled and Coupled (1). However, given two potential solutions within the same functional coupling category, Axiomatic Design technology cannot further rank these solutions without additional information. This paper proposes that the degree of functional coupling can be assessed to provide further discrimination between solutions within the same coupling category. Using complexity concepts, this paper proposes two additional metrics, the Independence Priority Number (IPN) and the Independence Measure (IM) to further rank the potential robustness of alternative solutions using the Independence Axiom of the Axiomatic Design process. With IPN and IM metrics, design professionals can better assess the functional robustness of their proposal at the earliest phase of design, conceptual design synthesis.