A fuzzy quality cost estimation method

Quality cost control is one of the most important aspects in the development of a quality management system. This paper presents a method for the estimation of quality cost that aims to take into account the so-called hidden quality costs, which are typically unobserved or unknown. Although this is a subject that has already been approached in other studies, subjectivity and uncertainty are not included in their formal approach, which any attempt to address hidden quality costs should include. Our methodology begins by observing the position each business occupies in Crosby's Quality Management Maturity Grid. Obtaining the stage index on the basis of the experts' opinions permits the valuation of the company's membership for each of the stages of Crosby's Maturity Grid. The application of Crosby's corrector coefficient to an adequate weighting of the stage index makes it possible to obtain the fuzzy number quality cost. The measures obtained and their short-term predictions enable us to know the situation at all times and act accordingly, establishing precise corrective plans that will correct tendencies and make continuous improvement possible.