A new insight into the Taguchi method.

To obtain high quality products at low cost and in a short time is an economical and technological challenge to today's engineering community. Design of Experiments based on the Taguchi approach is a powerful technique to attain this objective. In some processes, it is necessary to consider not only two factors but also the ratio of their levels 'as a factor.' This paper introduces a new look at the Taguchi method that makes it possible, by choosing the proper levels, to evaluate the ratio of two factors as a new factor in the same orthogonal array. An experiment to study four three-level factors was designed, and a case study is presented to illustrate the ratio of the two three-level factors as a new factor using the same L9 orthogonal array.