New prioritization of QFD's engineering characteristics through the Law of Comparative Judgment

The House of Quality (HoQ) is the key module of Quality Function Deployment (QFD), which aims to support the design of new products or services by translating customer requirements (CRs) into engineering characteristics (ECs). The independent scoring method is the most widely used technique for the prioritisation of ECs; despite this, it has two conceptual shortcomings: (i) arbitrary numerical conversion of (ordinal) relationships between CRs and ECs (i.e., null, weak, medium, and high), and (ii) "promotion" of these relationships from an ordinal to a cardinal scale. This paper introduces a novel procedure for prioritizing ECs, inspired by the Thurstone’s Law of Comparative Judgment (LCJ), which overcomes the conceptual shortcomings of the ISM while maintaining its flexibility and ease of implementation. A realistic application example illustrates the potential of the proposed procedure.