Quality costs: A critique of some ‘economic cost of quality’ models

While carrying out a study of the collection and use of quality-related costs in manufacturing industry the authors found in the literature many notional models purporting to indicate the relationships between the major categories of quality costs, and a few sets of real data. Despite being based on common principles, there are wide differences between some of the models, and between the models and real data. The paper categorizes and discusses the models in the light of the research experience. It is concluded that many of the models are inaccurate and misleading, and serious doubts are cast on the concept of an optimum quality level corresponding to a minimum point on the total quality-cost curve.