Optimum reassignment of degrading components for non-repairable systems

Abstract

The components in a system can degrade differently, due to the operational loads or environmental conditions, or both, in their positions being different. Therefore, reassignment of the functionally exchangeable components to the positions at appropriate time can increase system reliability and extend system lifetime. In this article, a new component reassignment problem is proposed, and a mixed binary nonlinear programming model is built to determine the optimal reassignment time and optimal reassignment of degrading components with the objective of maximizing system lifetime. The model integrates continuous optimization and combinatorial optimization, and provides a framework for optimizing the component reassignment decisions for various degradation models and system structures. Furthermore, the optimization model and analytical results are derived for k-out-of-n systems of linearly degrading components or exponentially degrading components. The analytical results reduce the complexity of solving the optimization model and are used to design an efficient solution method. Finally, numerical examples in a power supply system demonstrate applications of the optimization model and further provide managerial insights for the component reassignment problem of degrading components.

Keywords:

• Component reassignment problem
• degradation
• mixed binary nonlinear programming
• functionally-exchangeable components
• k-out-of-n systems

Additional information

Notes on contributors

Xiaoyan Zhu

Xiaoyan Zhu is a professor in the School of Economics and Management at University of Chinese Academy of Sciences, Beijing, China. She received a B.E. degree from Tsinghua University, Beijing, in 2000, and M.S. and Ph.D. degrees in industrial engineering from Texas A&M University, College Station, USA, in 2002 and 2005, respectively. Her research interests are in system reliability optimization, operations research, and supply chain andinventory management. She is a member of INFORMS and a senior member of IISE and IEEE.

Yuqiang Fu

Yuqiang Fu obtained a Ph.D. degree in management science from University of Chinese Academy of Sciences, Beijing, China. He received his B.S. degree in applied mathematics from the University of Petroleum, China. His research interests include mathematical modeling, design of reliability system and importance measures.

Tao Yuan

Tao Yuan is a professor in the Department of Industrial and Systems Engineering at Ohio University. He received a B.E. degree in thermal engineering from Tsinghua University, China, an M.S. degree in aerospace engineering and an M.E. degree in industrial engineering from Texas A&M University, College Station, and a Ph.D. degree in industrial engineering from the University of Tennessee, Knoxville. His research interests are mainly in reliability modeling, testing, and data analysis. He is a member of IISE and INFORMS, and a senior member of IEEE.