Morvarid Derakhshan Andisheh Journal of Quality Engineering and Management 3134-0849 2 2 2012 08 22 Robust Design Optimization for Time-Based Quality Indices Using the Utility Function Robust Design Optimization for Time-Based Quality Indices Using the Utility Function 78 88 235251 FA Mohammadreza Nabatchian Department of Industrial Engineering, Khajeh Nasiruddin Toosi University of Technology, Tehran, Iran. Hamid Shahriari Department of Industrial Engineering, Khajeh Nasiruddin Toosi University of Technology, Tehran, Iran. Rasoul Shafaei Journal Article The subject of time-dependent quality indices—whose values vary over time—has attracted significant attention from quality researchers in recent years. Various methods have been developed for this purpose, among which one of the most recent approaches involves analyzing performance profiles over time. Moreover, as competition among manufactured products intensifies, product design has become a primary focus within the product life cycle for manufacturing organizations. One of the most widely used approaches in this context is robust design. The application of response surface methodology and its related optimization tools has also gained great importance in design studies. In this article, a utility function–based method is presented for the robust design optimization of time-dependent quality indices. Based on the results obtained from a pharmaceutical case study, the proposed method performs significantly better than the two existing methods. The subject of time-dependent quality indices—whose values vary over time—has attracted significant attention from quality researchers in recent years. Various methods have been developed for this purpose, among which one of the most recent approaches involves analyzing performance profiles over time. Moreover, as competition among manufactured products intensifies, product design has become a primary focus within the product life cycle for manufacturing organizations. One of the most widely used approaches in this context is robust design. The application of response surface methodology and its related optimization tools has also gained great importance in design studies. In this article, a utility function–based method is presented for the robust design optimization of time-dependent quality indices. Based on the results obtained from a pharmaceutical case study, the proposed method performs significantly better than the two existing methods.