Complexity reduction of a design problem in QFD using decomposition

Abstract

Quality function deployment (QFD) is a cross-functional planning tool that ensures that the voice of the customer is systematically deployed throughout the product planning and design stages. Although many success applications of QFD have been reported worldwide, designers face impediments to the adoption of QFD as a product design aid. One of the difficulties associated with the application of QFD is the large size of a house of quality (HOQ) chart, which is the principal tool for QFD. It is well-known that it becomes more difficult and inefficient to manage a design project as the problem size becomes larger. This paper proposes to develop formal approaches to reducing the size of an HOQ chart using the concept of design decomposition. The decomposition approaches developed attempt to partition an HOQ chart into several smaller sub-HOQ charts which can be solved efficiently and independently. By decomposing a large HOQ chart into smaller sub-HOQ charts, the design team not only can enhance the concurrency of the design activities, but also reduce the amount of the time, effort, and cognitive burden required for the analysis. This would help to obviate the objections to the adoption of QFD as a product design aid and improve the efficiency of its use in practice.