Analysis of some reliability measures of single-unit systems subject to abnormal environmental conditions and arbitrary distribution for failure and repair activities

摘要

This article analyzes the effect of abnormal environmental conditions on various reliability measures. After the continuous operation of single-unit systems for a long duration of time these systems cannot be restored again in a younger state after the failure of the system. The unit does not remain as new after repair. This phenomenon is known as degradation and the unit after repair is called degraded unit. Preventive maintenance is a proactive method to tackle and overcome from these types of problems. For this purpose, a stochastic model is developed for single-unit systems by using semi-Markov process. There is a single server who inspects the failed unit after failed to check the feasibility of repair and replacement. If repair is not feasible then unit is replaced with some replacement time. The failed unit after repair becomes degraded and degraded failed unit is replaced by new one. All time distributions are arbitrary distributed like Weibull distribution with common shape parameter and different scale parameters. The switching devices are instantaneous. The system is observed at suitable regenerative epochs to obtain various measures of system effectiveness of interest to system designers and operation managers.