Cost-benefit analysis of a two-unit warm standby reliability system with two types of repair facilities

Abstract

This paper deals with the cost analysis of a two-unit warm standby system. Here the two units are identical but they have different failure time and repair time distributions when they have failed in an operating or standby state. Initially, one unit is operative and the other is kept as a warm standby. The failure times and repair times of the main and standby units are assumed to be arbitrarily distributed. When the operative unit fails, we wait for the repairman for some maximum time, or until the other unit fails; when the warm standby unit fails, we wait for the repairman until the other unit fails. On the failure of the second unit or on the completion of the maximum time, we call the repairman immediately at the higher cost. Explicit expressions for the mean time to system failure, the availability analysis, cost analysis and expected profit in steady state are obtained. Computer programs for calculating the MTSF and the profit of mode are given. Some previous results are derived from this work as special cases.