Optimization of multiresponse problems using process capability index for batch manufacturing processes

In this paper a new method in multi response experimental design is proposed to determine the optimal settings for controllable factors, where the responses are uncorrelated. This method leads to improving the quality characteristic with the lower process capability index (PCI) with more priority. Due to the application of this study in a batch manufacturing and existing of some parts in each treatment, PCI has been computed for each treatment for every initial response. Then an aggregated index (c_i) has been computed by TOPSIS based on the calculated signal to noise ratios of PCI´s. Finally the optimal controllable factors have been determined by optimizing a fitted linear regression to the aggregated index and values of controllable factors. The proposed method is illustrated by a real case study in a plastic molding factory. The results show the effectiveness of the proposed method in improving the quality characteristic with the lowest c_pk.