Model 1 is the current Navy policy. Model 4 is similar to Condition based maintenance (CBM). Perform maintenance according to the condition of the ship and start naval operation as soon as maintenance is completed. Models 2 and 3 are alternatives that can be used in the process of developing CBM from the current policy. Because the military is a conservative group, they tend to avoid innovative improvements. Models 2 and 3 can be used in this case.