A Method for Computing Weights of Engineering Metrics in QFD for Environment

In quality function deployment for environment(QFDE),to calculate accurately the weights of engineering metrics(EM)helps obtain better designs of product's function and environmental performance.A method for calculating the EM weights based on the extension engineering is proposed,which considers judgments from different experts and several influencing factors.The fuzziness judgments of the mapping relationships between the voices of customer and environment(VoCE)and the EM by different experts are represented with the extension interval numbers.The extension AHP method is applied to convert the extension interval numbers into precise weight values.In the House of Quality(HoQ),for computing the weights of the EM,four kinds of weights are considered simultaneously:the weights for evaluating self-correlations among the VoCE;the weights for evaluating competitiveness of the VoCE among competitors;the weights for evaluating self-correlations among the EM;and the weights between the VoCE and the EM.The HoQ method considers these various influencing factors and their fuzziness,so the weights of the EM computed can reflect the VoCE precisely,and the products designed with the EM are environmentally-friendly and competitive.A case study illustrates the implementation process and feasibility of the method proposed.