Analysis of a System Working under Different Weather Conditions with On-Line Repair and Random Appearance of the Server at Partial Failure Stage

In the present study two reliability models for a single-unit system working under two weather conditions - normal and abnormal are developed in which unit fails completely via partial failure. There is a single server who appears randomly at partial failure of the unit and remains with the system in abnormal weather. The server inspects the partially failed unit to see the possibility of on-line repair. If on-line repair of the unit is not possible, it is repaired in down state. In model I, the completely failed unit is repaired without inspection while in model II, the completely failed unit is replaced by new one if inspection reveals that repair of the unit is not feasible to the system. In abnormal weather, no inspection and repair of the unit are carried out while system remains operative. The distributions of failure time and change of weather conditions are assumed as negative exponential while that of inspection and repair are taken as arbitrary. The expressions for some reliability and economic measures are derived by making use of regenerative point technique. The numerical results for a particular case are obtained to depict the behaviour of MTSF and profit of the models graphically.