Assessing and controlling the availability of failure-degraded service agents

Abstract

Military items such as airborne surveillance systems (UAVs, JSTARS, helicopters, etc.) or combat vehicles (tanks, APCs, ships) may have high effectiveness when available on station, but require occasional restoration (refueling, re-arming, scheduled maintenance) and repair after unscheduled failures of certain subsystems. This requirement takes them off station, where delays occur that are affected by the numbers and types of support resources and the philosophy of scheduling those resources. This paper considers the effect of decision choices on long-run item availability on station when items can be in several levels of capability/effectiveness when on station. The model is used to show that a simple binary decision rule (that depends on ratios of endurance, failure, and restoration and repair rates) guides the decision as to whether a failed item should be completely repaired to its highest level, or returned to duty at an incompletely-capable state. View this as an indicator of the types of rules anticipated to apply in realistic generality. These will be the subject of additional research.