Determining economic maintenance frequency of a transport fleet

A total cost model has been developed for a transport fleet consisting of groups of vehicles. The total cost model considers two types of costs: (1) operating cost and (2) maintenance cost. The operating cost is assumed to increase with elapsed time since the last maintenance on the vehicles. The maintenance cost is assumed constant for each vehicle. However, a fixed cost must be incurred at the start of a maintenance cycle. The objective is to determine the operating and maintenance policy of the vehicle that minimizes the total of the operating and maintenance cost of the transport fleet.