An approach of new product planning using quality function deployment and fuzzy linear programming model

Quality function deployment (QFD) is a useful tool for maximising customer satisfaction in the new product planning (NPP) process. When applying QFD, recognising the importance levels of customer requirements (CRs) is a vital issue, since they have great influences on the values of decision variables, i.e. the fulfilment levels of design requirements (DRs), for NPP. Unlike existing researches, this study evaluates the importance scores of CRs from three different perspectives: the customer, competition and value perspectives. To cope with the vague and uncertain nature at the NPP stage, various fuzzy approaches are adopted for measuring the importance scores of CRs from different perspectives. The three measures are aggregated as the evaluated importance score of each CR. In addition, different to prior studies, this paper modifies Chen and Weng's model to develop a new normalised relationship between CRs and DRs to improve the existing models' drawbacks. A fuzzy linear programming model is established to determine the optimal fulfilment levels of DRs to maximally satisfy CRs. Based on an illustrative example, the proposed method achieves greater total customer satisfaction than previous methods. Furthermore, this paper also proposed a normalised relationship formulation with conventional way to reasonablely modify Wasserman's model.