In this paper, we focus on the optimal software testing/maintenance problem considered in Rinsaka and Dohi (2004), and develop a stochastic model in discrete operation circumstance, under the difference between the software testing environment and the operational environment can be characterized by an environment parameter. More precisely, the total expected software cost is formulated via the ...

This paper discusses an imperfect preventive maintenance model for a deteriorating repairable system with consideration of the reliability limitand random maintenance quality. The model is derived from the combination of failure rate adjustment and age over an infinite time horizon. The maintenance intervals are obtained assuming both the failure rate increase factor and age restoration factor ...

We design an optimal preventive maintenance policy for a system of N items that minimizes the total expected maintenance cost. We assume that the budget for preventive maintenance is limited and constrained. The problem has a finite time horizon and we consider constant inter-preventive maintenance times for every item. The resulting nonlinear optimization problem is reformulated as a binary in...

This paper discusses the problem of the optimization of maintenance threshold and inspection period for a continuously deteriorating system with the influence of covariates. The deterioration is modeled by an increasing stochastic process. The process of covariates is assumed to be a temporally homogeneous finite-state Markov chain. A model similar to the proportional hazards model is used to r...

Abstract: A condition based preventive maintenance (CBPM) policy is proposed for a continuously operating device whose condition deteriorates with time in service. The model incorporates both deterioration and random failures. Deterioration is modeled as discrete states process. The system undergoes random inspections to know the condition, mean time between inspections are exponentially distri...

Today, maintenance strategies and their analyses remain a worrying problem for companies. Socio economic stakes depending on competitiveness of each strategy are even more linked to activity and quality of maintenance interventions. A series of specific events can eventually warn the expert of an imminent breakdown. Our study aims at understanding such “signature” thanks to hidden Markov models...

We consider multicomponent maintenance systems with an F -failure group age-replacement policy: it keeps failed components idling until F components are failed and then replaces all failed components together with the nonfailed components whose age has passed the critical threshold age n for components of type n. With each maintenance action, costs are associated. We derive various unbiased gra...