Building Numerical Design Matrix and Managing Functional Couplings for Concept Improvement of The Existing Product

Abstract

Because parametric values are unknown during initial concept generation, the Axiomatic Design Theory uses the binary design matrix (DM) to represent the coupling relationship between functional requirements and design parameters. However, given an existing product, it would be possible to employ the numerical DM that has more detailed information than the binary DM to help improve the design concept. This paper proposed a two-phase method to create a numerical DM in phase I and manage the functional couplings in phase II for concept improvement of existing product. A decomposition-definition-levelling framework and the Puritan-Bennett’s 0-1-3-9 level rating are employed to evaluate the system impact of each functional coupling to create the numerical DM of an existing design concept. The Design Coupling Sequence (DCS) approach was extended to use the numerical DM to improve this design concept. Compared with other numerical matrices for product development and the structured approach by Su et al., our method is more generic and faster, providing useful details yet still able to maintain the dominance of the high-level couplings.