A single unit system with preventive maintenance and repair subject to maximum operation and repair times

Abstract

The purpose of the present study is to determine reliability measures of a single-unit system considering arbitrary distributions for the random variables associated with failure time, preventive maintenance and repair times, maximum operation time, maximum repair time and replacement time. The system fails completely either directly from normal mode or via partial failure. There is a single server who visits the system immediately to do repair activities. The partially failed operating unit is shutdown after pre-specific time (called maximum operation time) for preventive maintenance. However, repair of the unit is done after its complete failure. The completely failed unit is replaced by new one if server is unable to do its repair within a maximum repair time. The unit works as new after preventive maintenance and repair. The expressions for some important measures of system effectiveness are derived using semi-Markov process and regenerative point technique. The numerical results for a particular case are obtained to depict the behavior of MTSF, availability and profit function with respect to maximum operation time for fixed values of other parameters and costs.