Methodological Research Of Conceptual Design Based On Quality Function Deployment

The quality of the conceptual design will determine the fate of product. It's an important practical question to the government, business and academic that how to carry out conceptual design to meet customer needs to the highest extent, how to apply the quality management method to improve the efficiency of the conceptual design, and how to enhance the innovation capability of enterprises in the context of limited resources. The theory of quality function deployment (QFD) can provide a systematic research framework for conceptual design in the research and development (R&D) for product. It is of great theoretical and practical significance to improve China's capability of independent innovation and enhance core competitiveness of enterprises that how to improve the method of conceptual design in the framework of QFD, to express and transmit information more effectively in the conceptual design stage, to resolve technical conflicts, to choice the conceptual design solution to the maximize customer satisfaction and to explore the available product innovation theories and methods.A system analysis framework which combined the economic and technical means-conceptual design analysis methods which embodied multiple methods based on QFD is proposed on the basis of a review of existing studies of conceptual design. The affinity diagram (KJ method), analytic hierarchy process (AHP). rough sets (RS), attractive quality theory (KANO model), theory of inventive problem solving (TRIZ) and the intuitionistic fuzzy sets (IFS), etc. are embodied the house of quality(HOQ) of QFD. Meanwhile, the author constructs the algorithm for importance of the customer needs based on modified RAHP and KANO to express customer needs. The single feature law is introduced into the meta-analysis framework of QFD and TRIZ to resolve technical conflicts for designers. Finally, the IFS is applied to deal with the conceptual design evaluation of uncertain, multi-attribute group decision making and provide the decision support for conceptual design evaluation.The main result and innovation of this dissertation makes is the core conceptual design analysis tool which embodied many methods based on QFD-the HOQ for conceptual design. The house of quality (HOQ) for conceptual design consists of twelve parts-the customer needs analysis based on KJ method, the basic algorithm of the importance of customer demand based on rough AHP (RAHP), the classification of customer demand based on KANO model, the market competition analysis, the algorithm of the importance of customer demand based on RAHP and KANO. the analysis of technical characteristics, the correlation matrix of technical characteristics, the relationship matrix of customer needs-technical characteristics, the importance degree algorithm of technical characteristics, the target location model for conceptual design, the conceptual design innovation methods and processes based on TRIZ and the optimization program models based on IFS. The various parts of the HOQ of conceptual design are closely integrated and mutually reinforcing. On the one hand, the HOQ of conceptual design provide method support with the integration of a variety of related methods to empress and transfer the ambiguity, uncertainty and vague information of customer demand, search innovative thoughts to meet customer needs and optimize the conceptual design program. On the other hand, the HOQ of conceptual design used a combination of economic and technical analysis methods study the decisions problem in conceptual design and resolve systematically the core question in conceptual design, i.e. how to maximize the customer satisfaction in the conditions of limited resources in the conceptual design phase.A series of cases of a steering wheel verified that the HOQ of conceptual design which embodies multiple methods based on QFD and the integration of related methods are feasible and effective, develop the QFD theory and improve the existing methods of conceptual design with a strong theoretical and practical value.