A Graphical Method to Assist Quality Decisions throughout the Product Development Process

Abstract

ABSTRACTIn product development processes and in the engineering world in general, many situations arise in which a decision must be taken to choose the best alternative or concept from among several already existing ones. Among the most used methods in situations like these are those that use two-dimensional decision matrices, where the concepts or alternatives are compared by evaluating them according to the degree of compliance for preestablished quality criteria.The finally adopted decision is not only conditioned by the decision maker's assessment of each alternative but also by the weightings initially assigned to the criteria. This means that variation in the assessment of any alternative or in the weighting of a criterion can lead to a distinct alternative being selected. In this article, we propose a graphical method that makes it simpler to view the margin for variation, for both the assessments of the alternatives and the weightings for the quality criteria, that does not affect the finally adopted decision. In this way, the decision-making team can analyze in greater depth the more critical assessments and weightings that, although consisting of small changes, could affect the decision. Finally, the applicability of the proposed method is demonstrated in a case study involving an electrical switch design.