One approach to evaluate the influence of engineering characteristics in QFD method

Evaluation of engineering characteristics (ECs) according to customer requirements (CRs) is the most decisive step of the house of quality in quality function deployment (QFD) method. In most cases, high degrees of correlation between ECs exist and should be modelled. The paper develops a specific measure ('influence gap') and novel underlying procedure (smallest gap technique) for ECs evaluation aiming to capture all interdependencies. The influence gap enables to characterise each EC according to its distance from ideal-maximum influence on all requirements. The relationships between CRs and ECs and their inter-relationships are obtained using interval-valued fuzzy DEMATEL method. From the practical point of view, the most important information for decision maker(s) generated by the model is the clear insight about the contribution of each EC when launching a new product/service. Practicability and usability of the proposed methodology is illustrated over a specific transportation service. [Received: 6 January 2018; Accepted: 2 December 2018]