The analysis described in this report suggests a new metric-the mission-day-to identify and examine the ability of the mobility air forces (MAF) to conduct missions, train its forces, and maintain readiness for new operations. Specifically, the mission-day metric can help the MAF detect and identify problems caused by the operations tempo (OPTEMPO) of MAF personnel. The mobility OPTEMPO is driven primarily by two categories of missions. The first category is missions that involve maintaining readiness to accomplish the tasks demanded of the mobility forces during major theater operations. These tasks include the delivery of troops and material to combat theaters, providing tanker support to mobility and combat aircraft in transit, and performing other specialized missions such as dropping paratroops. The second category of mobility missions is support of U.S. forces engaged in peacetime operations around the world. These include the support of small-scale contingencies (SSCs), humanitarian relief operations (HUMROs), presidential travel (called BANNERs), and other short-notice and high-priority missions flown on a daily basis (see Chapter 2).