Reliability-based maintenance optimization for the leased equipment with deterioration depending on age and usage

In this paper, we first consider a two-dimensional lease region that is composed of age limit and usage limit, and then from the leaser’s perspective develop maintenance policies so that the total cost in the lease region can be reduced. Deterioration process of the equipment is simultaneously dependent on age and usage. When reliability drops to a threshold, called reliability threshold, Preventive Maintenance (PM) is carried out to improve reliability. This repeated PM action is ceased until the associated remaining lease limits terminate. Under the situation that the lessee’s usage rate is single usage rate class, a unified maintenance policy is used to maintain reliability of the equipment. Under the situation that the lessee’s usage rate is classified, customized PM integrating with usage rate class is used to maintain reliability. We derive the leaser’s total cost models that are respectively related to a benchmark lease contract with the unified maintenance policy and the proposed lease contract with customized PM. By means of Root Mean Square (RMS), lease contract selection is performed. An example experiment is provided to verify the proposed methodologies. As showed in the example experiment, optimal values can be searched by minimizing the total cost and the proposed lease contract is beneficial for both the leaser and the lessee.