Scheme Evaluation Of Electromechanical Product Based On QFD

Quality function deployment, a kind of product developing method driven by customers, transfers customer requirement to product characteristic, part characteristic, technics characteristic and quality and production plan. Thus, the product can truly satisfy the customer requirements.Aiming at the trait of customer satisfaction theory and actual requirement, the dissertation researched the key evaluation techniques of the schemes of electromechanical product oriented to customer satisfaction based on the fruit of quality function deployment and related product scheme evaluation theories. An electromechanical product evaluation model and method based on improved QFD and entropy theory (I-QFD-E) was brought forward. The main content is as following:The concept of product quality oriented to customer satisfaction was extended to the whole cycle of the product. Compared with the traditional product quality, modern product quality requires to meet the customer requirement around the whole life cycle. The dissertation extended the product quality from two aspects:product quality was extended to the technical performance, economical performance and social influence from transverse aspect while from the lengthways aspect the product quality was extended to the whole life cycle, that is, from market investigation to product reclaim to consider the factors of product quality.Traditional QFD framework was improved. According to the basic principle of QFD, the improve framework extended QFD to the phases of distribution and reclaim. Therefore, customer requirement was extended to the whole life cycle, which fulfilled the waterfall decomposing of product life cycle oriented to customer requirement.Traditional house of quality adopts the discrete scales to value customer requirement and related design requirement. In this way, not only the precision is very low but the structure of traditional house of quality limited the use of multi-attribute evaluation method. An attribute weight confirming method, I-QFD-E, had been researched. This method had been brought forward to value the weight of design requirement. First, AHP was adopted in the QFD model to acquire the first weight. Then the entropy theory was adopted to get the revised weight. In this way, the result avoids the disadvantage of AHP of over-subjective. Meanwhile, the new method offsets the disadvantage of entropy theory of absolute impersonal without the support of experts. The results optimized the weight of each factor and truly reflected the customer requirement.The product scheme evaluation model was established based on I-QFD-E. According to the variety of attributes, fuzzy evaluation theory, grey evaluation theory and extension evaluation theory based on I-QFD-E had been researched. Finally, these three kinds evaluation theories including six evaluation methods had been testified by a case.A fuzzy evaluation method based on I-QFD-E and an evaluation method based on I-QFD-E and Euclid norm which have solved the subjective problem during the judging procedures and the aim of transferring the qualitative attributes to quantitative attributes had been achieved. The fuzzy evaluation method based on I-QFD-E has great applicability aiming at the problem with many levels while the evaluation method based on I-QFD-E and Euclid norm transfers the multi-object problem to single objective problem.A grey relation projection evaluation model base on I-QFD-E improved the traditional grey method by ameliorating the identification coefficient. The new model first established the relation among the optimal sequence and actual schemes using the limited information. Then the grey relation projection was integrated in the evaluation model. Therefore not only the distance similar degree was considered but the direction among sequences was resolved. The fuzzy grey comprehensive evaluation mode based on I-QFD-E was established. The new model solved the problem of the fuzzy input and grey characteristic in small-batch.The multilevel priority degree evaluation method based on I-QFD-E and the extension evaluation method based on I-QFD-E had been established. The multi-level priority degree evaluation method based on I-QFD-E can deal with the scheme with a good deal of guidelines and achieved the sequence by priority degree. The extension evaluation method based on I-QFD-E can partition the scheme rank, thus the evaluation procedures have been predigested. Both of the methods give prominence to irreplaceable condition, reduce the dimension of scheme and calculation quantity and transfer the incompatible problem to consistent problem. Both of the methods combine the qualitative guidelines with quantitative guidelines.The evaluation software system had been developed by using Visual C++6.0. Each functional module calculates the scheme value and sequences the schemes under fuzzy theory, grey theory and extension theory.