Technical importance ratings in fuzzy QFD by integrating fuzzy normalization and fuzzy weighted average

Fuzzy quality function deployment (QFD) has been extensively used for translating customer requirements (CRs) into product design requirements (DRs) in fuzzy environments. Existing approaches, however, for rating technical importance of DRs in fuzzy environments are found problematic, either incorrect or inappropriate. This paper investigates how the technical importance of DRs can be correctly rated in fuzzy environments. A pair of nonlinear programmingmodels and two equivalent pairs of linear programmingmodels are developed, respectively, to rate the technical importance of DRs. The developedmodels are examined and illustrated with two numerical examples. © 2011 Elsevier Ltd. All rights reserved.