Reliability system with two types of repair facilities
Abstract This paper deals with two identical unit cold stand-by systems. Two types of repair facilities, having a considerable difference in their costs, are used to repair the units. Repair of type 2 facility, a costlier one, is always available, while for repair of type 1 facility one has to wait for some time. If this waiting time exceeds some given maximum time, one has to call costly repair i.e. repair of type 2 facility. The system has been analysed to determine the reliability measures viz. MTSF, steady state availability, expected number of repairs etc., by using theory of semi-Markov processes and regenerative processes. Integral equations are set up for deriving these measures. These equations are solved with the help of Laplace transform technique. A cost equation is derived. The condition for maximizing the profit is also derived. Certain particular cases are analysed.