Multiple comparisons with the best for supplier selection with linear profiles

In some manufacturing processes, the quality of a process or product is characterised by a linear profile. Comparing the process yield of multiple suppliers with linear profiles is an important task in supplier evaluation. In this study, we consider linear profiles with two-sided specifications and present the multiple comparisons with the best method based on the process yield index to select the best supplier. A subset contains the best supplier determined from the confidence interval of the difference between the process yield indices of the unknown best supplier and all of the suppliers. A simulation study is used to conduct the statistical power analysis. The results confirm that the larger the number of levels or the number of profiles, the larger the power of test. The simulation results indicate that our proposed method can effectively identify the best supplier. Two real examples are used to illustrate the applications of our proposed method.