7. Introduction to the Taguchi Method

We now introduce a further powerful engineering tool: the Robustness concept. It is inextricably linked to the name of Genichi Taguchi, a Japanese engineer. Although his approach is based on what was outlined in the previous chapter on Design of Experiment, it contains strong innovation of those concepts. Significant improvements are proposed for three design phases: system design, parameters design and tolerance design. It is not possible to draw a comprehensive picture of the method here. Only the main concepts are introduced, leaving any more complex treatment of the method to specialized books. This method is a real improvement of the application of statistical methods to design applications. This chapter describes the basic concepts, among which the Quality Loss Function that better than other interpretations clarifies the term, often ambiguous, of quality. In this way, the link between robustness, reliability and design of quality becomes obvious. We tried to give emphasis to ideas more than to technicality, but a limited mathematical formalism is necessary.