Feasibility of analytical solution for transient availability using semi‐Markov process

In this paper, an analytical method for the transient solution of the semi‐Markov model for availability analysis of repairable mechanical systems is explored. Currently, simulation software, such as Blocksim and RAPTOR, is being used mostly to solve such models. It is well known that for mechanical systems and their components, degradation rate increases with ageing process and the Weibull distribution for the time to failure is the most appropriate for such systems. Therefore, the Semi‐Markov Process (SMP) model is developed for repairable mechanical systems. Since the involved integrals in the analytical solution of the SMP model with typical Weibull parameters could not be solved, the transient probability solution of states is obtained for a special case. These states, probability values lead to evaluation of the system availability. The transient solution is also obtained by the Monte Carlo simulation that matches with the analytical solution obtained from the SMP model.