Designing-in of Quality Through Axiomatic Design

Abstract

Decisions made during the design stage of product & process development profoundly affect product quality and process productivity. To aid in design decision making, a theoretical framework is advanced: the axiomatic approach to design. Axiomatic design consists of: 1) domains in the design world, 2) mapping between these domains, 3) characterization of a design by a vector in each domain, 4) decomposition of the characteristic vectors into hierarchies through a process of zigzagging between the domains, and 5) the design axioms, viz, Independence & Information Axioms. Statistical process control (SE) and other methodologies to improve quality are valid only when they are consistent with the Independence & Information Axioms. This paper presents several criteria that govern the design & manufacture of quality products, To be able to control the quality of products, a design must satisfy the Independence Axiom. Based on this axiom and some theorems, several design criteria are derived & discussed. These criteria provide the bounds for the validity of some of the SPC techniques being used. When there is more than one acceptable design of a product or process, the Information Axiom must be used to select the best design(s).