Investigation of Mean Time to System Failure of Fuzzy Semi-Markovian Repairable Redundant System

The prominent objective of present work is to analyze the impact of preventive maintenance (PM) on the mean time to system failure (MTSF) of non-identical units’ redundant systems. A stochastic model is developed using the concept of priority to PM of original unit over repair of duplicate unit. The failure, repair and maintenance rates followed the Erlang distribution having two parameters with fuzzy parameters. The fuzzy parameters follow the bell-shaped membership function. The rate parameter is estimated for a particular value of shape parameter by generating the random samples to estimate the fuzzy mean values of the parameters and mean time to system failure. Numerically, a comparative analysis of mean time to system failure is performed.