Modeling and evaluation of MTSF of a repairable 2-out-of-4 warm standby system attended by repair machines and repairmen

Abstract

Studies on reliability characteristics of a redundant repairable warm standby system are numerous. Little literature is found in the use of repair machines and a repairman to repair the failed unit and failed repair machine. This paper presents analysis and evaluation of mean time to system failure (MTSF) of a repairable 2-out-of-4 warm standby system. The system comprises of two subsystems A and B arranged in series. Subsystems A and B are two units warm standby. The system work provided one unit each of subsystem A and B are working while the remaining two units are in warm standby. The system is attended by two repair machines and two repairmen assigned to each subsystem to repair any failed unit and failed repair machine respectively. An explicit expression for mean time to system failure (MTSF) is derived and analyzed using Kolmogorov’s forward equation method. Numerical simulations using assumed numerical values giving to the system parameters have been obtained.