A proposed satisfaction function model to optimize process performance with multiple quality responses in the Taguchi method

Abstract

The Taguchi method has been found effective for optimizing a single quality response. In reality, customers are concerned about multiple quality responses of a product. Although several approaches have been proposed to deal with this issue, however they ignored engineers’ satisfaction regarding process factor settings. This research, therefore, proposes an approach for optimizing multiple responses in the application of the Taguchi method. The mathematical relationships between each response quality and process factors are first formulated. Then, a proper satisfaction function is selected to represent each response and process factor. A complete optimization model is developed. Three case studies are provided for illustration; in all of which the proposed approach provides the largest improvement percentages while considering process engineers’ satisfaction about process factors. Compared to previous approaches in literature, such as gray analysis and fuzzy-gray analysis, the proposed approach provides optimal solution within factor setting ranges, relies on mathematical relationships between response and process factors, and considers engineers’ preference regarding process factor settings. Definitely, the proposed approach shall provide practitioners a great assistance in optimizing performance with multiple responses while considering their preferences about responses as well as process factor settings.