Development of a Robust Design Process Using a New Robustness Index

In product design and manufacturing, robust design leads to a product that has good quality. Robust design is reviewed in two categories: one is the process and the other is the robustness index. The process means efficient manipulation of the mean response and the variance. The robustness index indicates a measure of insensitiveness with respect to the variation. To improve existing methods, a three-step robust design (TRD) is proposed. The first step is “reduce the variance,” the second is “find multiple candidate designs,” and the third is “select the optimum robust design by using the robustness index,” Furthermore, a new robustness index is introduced in order to accommodate the characteristics of the probability of success in axiomatic design and the Taguchi’s loss function. The new robustness indices are compared with the existing ones. The developed robust design process is verified by examples and the results using the robustness index are compared with those of other indices.