Two models for two unit warm standby redundant system with two different kinds of repair and tolerable time

Abstract

This paper investigates the probabilistic behaviour of two models for two unit warm standby redundant systems having one regular and one expert repairman. The expert repairman is used if the regular repairman is not able to complete the repairs within some tolerable time. In model 1, the regular repairman can always repair unit failed from standby state. In model 2, the regular repairman sometimes may not be able to repair operative also the warm standby within some tolerable time and then we call the expert repairman. Explicit expressions for the mean time to first failure, the availability analysis, busy period analysis the expected number of calls for the expert repairman and cost analysis are obtained in each model. The results obtained by [4] are derived from the the present results as special cases. Computer programmes for calculating the MTSF and the profit of both models are given (see appendix).