A Standby System with Priority to Repair over Preventive Maintenance

A cold standby system of two identical units is analyzed stochastically under priority in repair disciplines. Unit has a constant failure from normal mode. There is a single server who visits the system immediately to carry out repair activities. Server conducts preventive maintenance of the unit after a pre-specific time‘t’ of operation. However, repair of the unit is done by the server at its failure. Priority is given to repair of one unit over preventive maintenance of the other unit. The random variables associated with different rates are statistically independent. The failure time and time by which unit goes for preventive maintenance follow exponential distribution while the distributions of maintenance and repair times are taken as arbitrary with different probability density functions. The expressions for several reliability measures of the system are derived using semi-Markov process and regenerative point technique. Graphs are drawn to depict the behavior of MTSF, availability and profit function for particular values of various parameters and costs