Optimum maintenance policy using semi-Markov decision processes

A method is presented to solve for the optimum maintenance policy of repairable power equipment. A semi-Markov decision process (SMDP) is utilized to determine whether maintenance should be performed in each deterioration state and, if so, what type of maintenance. The approach uses a model that assumes equipment can fail due to both deterioration and random occurrences. Preventive maintenance can be performed from each working state to prevent deterioration failure. Minor maintenance will most likely return the equipment to the immediate preceding working state, while major maintenance can return the equipment to any of the previous working states. An example is used to demonstrate the method using MATLAB software.