Although many success applications of quality function deployment (QFD) have been reported worldwide, designers face impediments to the adoption of QFD as a product design aid. One of 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. 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 cannot only enhance the concurrency of the design activities, but also reduce the amount of time, effort, and cognitive burden required for the analysis.