Design for quality based on product key quality characteristics

Firstly, quality characteristics (QCs) are defined, the three-layer model and technical connotation of quality characteristics are presented, then the concept of key quality characteristics (KQCs) is presented and its evolution process model is created, and the key activities of KQCs evolution are discussed in the context of design for quality (DFQ). The design chain and new approach of DFQ based on KQCs are given. Identification method of KQCs is given by means of the house of quality. Decomposition method of hierarchical tree of KQCs is studied based on functional and physical tree in axiomatic design (AD). and the quality relation weight assessment process of its nodes based on their history data of quality related to noise and fault analysis is discussed in detail by means of rough set and fuzzy technique for order preference by similarity to ideal solution (TOPSIS). Results of generation, simulation and evaluation implemented quality of assurance plan are studied farther. Finally, case studies of typical mechanical products are offered. Applying the principle of the method presented, the case studies discuss the DFQ mode, the procedures of identifying KQCs, building the hierarchical tree of KQCs and verifying quality assurance plan. The test results of simulation and physical prototype show the validity and promise. Therefore, it provides a new practical approach for design for quality.