Multi-response optimization using weighted principal component

Taguchi method is a very popular offline quality design. However, it cannot solve the multi-response problem which occurs often in today's society. Research shows that the multi-response problem is still an issue with the Taguchi method. Researchers have tried to find a series of theories and methods in seeking a combination of factors/levels to achieve the situation of optimal multi-response instead of using engineers' judgement to make a decision in the Taguchi method. In 1997, Su et al. submitted the multivariate method, and in 2000 Antony proposed principal component analysis (PCA), to solve this problem. But with the PCA method, there are still two main shortcomings. In this study, the weighted principal components (WPC) method is proposed to overcome these two shortcomings, and three cases in their papers will be illustrated and compared in the application of WPC method. The result shows that the WPC method offers significant improvements in quality.