Balancing flexibility and inventory in repair inventory systems

In repair inventory systems, failed units are exchanged for serviceable units upon failure. The probability that serviceable units are available to support the exchange process can be used as a measure for the performance of the system. This measure is commonly called the expected fill rate. The expected fill rate is affected, among others, by the inventory of failed and serviceable units and the jlexibility of the manpower to adjust their repair rate. lt is assumed that, as a result of the manpower flexibility, the repair rate increases with the number of failed units. To obtain a target fill rate at minimum cast, bath the inventory and the manpower flexibility should be jointly considered. This joint consideration of inventory and jlexibility on cast with respect to a target fill rate is the subject of this paper. The consequences of such joint consideration for the process of designing control systems is discussed in conclusion.