System Reliability Analysis Based On Different Maintenance Strategies

ABSTRACT:In this paper, we derive two models focusing on the application of reliability theory. Specifically, in the first one, we investigate two unrepairable series systems with k-out-of-n(G) subsystems. The first system consists of a k-out-of-n(G) subsystem and a series subsystem while the second one consists of two k-out-of-n(G) subsystems. We assume the systems have identical components with identical lifetime distributions and the working components are suspended as soon as the systems are down. We propose Markov models for the reliability analysis of such unrepairable systems arising in some fault tolerant systems. We conduct a study regarding the reliability of system by hot redundant replacement parts. Some closed form results on the reliability and the mean time to failure (MTTF) are presented. Some numerical examples are given to illustrate the impact of several parameters on the reliability of the system. In the second one, we propose a maintenance scheme for leased equipment using linear failure rate reduction method and derive an optimal preventive maintenance (PM) policy that minimizes expected total cost. Under the proposed maintenance scheme, the lessor (equipment owner) rectifies failures with minimal repairs within the lease period. To reduce the expected total cost, the lessor may employ PM actions to decrease the number of possible failures. In this study, the optimal preventive maintenance time epochs are presented. The optimal PM action times is obtained to derive the optimal PM policy for the case where the lifetime distribution of the equipment is Weibull. Finally, an efficient algorithm is developed to find the optimal parameters and the minimal cost and some numerical examples are obtained to describe the relationship between the total cost and the parameters.