Metrics, Key Performance Indicators, and

There are numerous parameters that influence the availability of long range aircraft. In order to develop models evaluating aircraft availability, an understanding of these parameters, along with the corresponding metrics, is required. An analysis of historical data for a modern long range transport aircraft shows that unscheduled organizational-level maintenance and depot maintenance are the largest contributors to downtime. A similar analysis of a legacy long range strike aircraft shows that unscheduled unit-level maintenance is a driver, but also shows that supply delays are a significant contributor to aircraft downtime. Boeing’s System Health Operational Assessment Model (SHOAM) is described, along with the results of a case study that identifies maintenance infrastructure as the key drivers for long range aircraft availability. 1.0 INTRODUCTION “Availability is a measure of the degree to which an item is in an operable state and can be committed at the start of a mission when the mission is called for at an unknown (random) point in time.”[1] There are numerous parameters that influence the availability of long range aircraft. These parameters, which can be categorized into those associated with aircraft design, maintenance infrastructure, and operations, are defined along with their associated metrics. An analysis of historical data is provided to gain insight into availability drivers. Finally, a Boeing developed model that can be used to determine the sensitivity of availability to various parameters is described along with the results of a case study that identifies the key parameters for long range aircraft availability. 2.0 PARAMETERS AND METRICS In simplest terms, availability is calculated by dividing system up time by total time. However, as seen in Figure 1, there are many components of system downtime that affect availability. Each of these components has a set of associated parameters and metrics that must be understood in order to calculate aircraft availability. These parameters can be categorized into those associated with aircraft design, maintenance infrastructure, and operations. Metrics, Key Performance Indicators, and Modeling of Long Range Aircraft Availability and Readiness 7 2 RTO-MP-AVT-144 Time Total Time Down Time Total or Time Total Time Up ty Availabili − =