Degradation-based Optimal Swapping Policy.

[摘要] Asset management is typically coupled with maintenance management as every system, machine, or tool is bound to degrade. In many disciplines, we are faced with a system of identical assets or components that are used differently. The difference in usage is attributed to the loading profile at which these assets are operating, or the frequency of their usage. With time, the degradation of the assets will reach a level, which can result in partial or complete loss of the system performance or functionality. This is usually met by maintenance actions (substitutions) performed on the degraded assets to restore the functionality of the system, which can be significantly costly. We propose a policy, denoted as the Degradation-based Optimal Swapping (DBOS) policy, which incorporates optimal implementation of swapping and substitution actions throughout a plan of finite time horizon to minimize projected maintenance costs. The swapping action refers to the inter-change in the placement of two assets from two different loading profiles. The substitution action refers to the replacement of the degraded assets with new ones. The degradation-informed resource allocation policy takes advantage of the different degradation rates in the assets;; health states, due to the different loading conditions, achieving optimal placement at different time intervals throughout the plan horizon. For the primary application of the policy, the fleet-level battery utilization for electric or hybrid-electric fleet management, the policy is shown to establish substantial savings in the projected maintenance costs compared to other policies through promoted utilization of the highly costly and degradable Li-ion batteries. The policy is further developed to account for uncertain degradation estimation employing the Stochastic Dynamic Programming (SDP) and the Markov Decision Processes (MDP) framework. Finally, the policy is integrated with perishable spare parts inventory management to achieve simultaneous optimal fleet management and optimal replenishment.

[发布机构] University of Michigan

[效力级别] Swapping Policy

[关键词] Degradadtion-informed Resource Allocation Policy;Swapping Policy;Intelligent Maintenance;Optimization;Mechanical Engineering;Engineering;Mechanical Engineering