Optimum Preventive Maintenance Policy for a Mechanical System Using Semi-markov Method and Golden Section Technique

This paper presents a method to determine an opportune time interval to carry out preventive maintenance for a two component series system to maximize system availability. Owing to the fact that the failure and repair distributions of most of the systems follow non-exponential distributions such as Weibull, Log-normal, Gamma, etc. and preventive maintenance is carried out at fixed intervals of time, the Markov method becomes inapplicable. The Semi-Markov approach which can handle non-exponential distributions provides a realistic analysis of such systems. The Semi Markov process model is solved to evaluate steady state system availability using the two-stage analytical approach. The resultant system availability result is validated using the Monte Carlo Simulation. The preventive maintenance interval time for optimal system availability is then determined using the Golden Section Search technique.