Book Description

This monograph describes a model for evaluating the combined capacity of organic (U.S. Air Force owned and operated) and contractor maintenance assets to meet aircraft programmed depot maintenance (PDM) workloads. The PDM Capacity Assessment Tool (PDMCAT) forecasts the average number of aircraft that will be in PDM status each year over several decades, based on the initial number of aircraft in PDM status, the physical capacity of the facility or facilities (number of docks available for conducting PDM work), the PDM induction policy (the period allowed between the completion of one PDM and the start of the next), and the minimum hands-on flow time (the minimum time it would take a facility to complete a PDM if only one aircraft were in PDM status). While not directly part of the model, the derived induction data can be used to estimate both near- and long-term obligation authority requirements for different induction policies, labor rates, and workload forecasts. To illustrate the model's operations and capabilities, we applied the model to evaluate the U.S. Air Force's current capacity for supporting KC-135 PDM and examined several options for improving both near- and long-term availability. In the process, we discovered that, while future annual fleet costs increase and availability decreases with age and workload, they do so rather less rapidly because the aircraft induction rates (the number of aircraft inducted each year) decrease as the PDM flow time increases. This leads to a less-drastic cost and availability forecast than usual.