مقایسه دو سیاست نگهداری برای یک سیستم چند واحد با توجه به میزان تولید و تقاضا

The expected long run cost rate model is developed for a general multi-unit system to determine the optimal level. The maintenance model and the maintenance policies presented in this paper are new research contributions to the area of modeling and maintenance control of multi-unit systems. Our objective is to determine the optimal parameters for both maintenance policies minimizing the long run expected average cost per unit time. The developed optimization algorithms provide also the optimal inspection intervals for each policy. The problem is formulated and solved in the semi-Markov decision process (SMDP) framework. Numerical examples are carried out to demonstrate the proposed optimization model and to compare the two maintenance policies. Sensitivity analysis is conducted to observe the effect of number of turbines, distribution of replacement time, and several cost components on the optimal level and on the long run expected average cost rate.