Ranking Customer Requirements in QFD by Factoring in Their Interrelationship Values

Abstract

Quality function deployment (QFD) is a methodology used to achieve higher customer satisfaction. The engineering characteristics (ECs) affecting product performance are designed to match the customer requirements (CRs). Computing raw weights of CRs and priority scores of ECs from various input variables is one of the most critical phases in QFD application. This study deals with the most neglected and often-omitted part of the QFD process—the interrelationship matrix among customer requirements. This article presents a mathematical solution to the correlation triangle problem that incorporates both CRs and ECs. An attempt is made to address the issue by considering the impact of these interrelationships on the overall calculations, using weighted average method for the CR interrelationship value operator in order to prioritize customers' requirements in QFD. The outcome of the study is a mathematical solution to the perennial correlation triangle problem in the form of a framework that factors in the correlation triangle values in conjunction with computed raw weights for customer requirements. The model fine tunes and adds precision to an otherwise qualitative strategic decision process. The applicability of the authors' proposed model is demonstrated with a real-life example.