STRUCTURE AND FREQUENCY OF PRODUCT NONCONFORMITIES IN THE CONTEXT OF CUSTOMER SATISFACTION

The main goal of this paper is to evaluate the non-conformity of a product from the end-user point of view (assessment of conformity through second-party audits). A test sample of 510 reports about the estimation of compliance with the end-user requirements included. In doing the research, we identified 246 non-conformities, which we classified into three categories, documentation non-conformities, non-conformities established by verification, and non-conformities determined by validation. Empirically, we found the most significant group of non-conformities and calculated confidence limits for this group by using the beta distribution. We applied this type of distribution because it is a very flexible type, and it covers a wide range of different shapes depending on the values of parameters. The analysis of the obtained quantitative indicators of non-conformity showed that the purpose of the product is of the utmost importance to the end user. In connection with the non-conformity indicators, we analyzed the requirements of point 8.2 "Requirements for products and services" of ISO 9001:2015. In accordance, the manufacturer recommends the aspects on which to focus during the process of designing, developing, manufacturing and defining the requirements of the quality of its product.