A quality function deployment methodology with signal and noise ratio for improvement of Wasserman’s weights

Quality function deployment (QFD) has attracted much attention in not only the quality management field but also other engineering fields. The original concept of QFD is focused only on the voice of customers, which means that the needs of customers should be satisfied from the design stage of products. However, some problems were found in using subjective and qualitative data when constructing a house of quality (HOQ). To solve the problems, Wasserman presented a methodology to consider correlation weights on the top matrix of HOQ, but the weights are subjective data and can not guarantee consistency and objectivity. The Wasserman’s weights are randomly determined under subjective conditions. This research applies Taguchi’s robust design method as another method for obtaining the HOQ top matrix weights. With the new weights, S/N-QFD is deployed, and the result of S/N-QFD is compared with W-QFD. As an application example, with a real process and quality data of a representative company product, the relationship and the correlation between the process characteristics and the quality characteristics are analyzed. Finally, this paper presents a new QFD processing methodology to determine the weights with more consistent and objective data.