AVAILABILITY OF WEAPON SYSTEMS WITH LOGISTIC DELAYS: A SIMULATION APPROACH
The availability of weapon systems such as fighter aircraft, battle tanks and warships during high intensity conflicts becomes low. In this paper the availability of fighter aircraft with five major subsystems (structures, engine, avionics, electrical and environmental) are considered. This depends mainly on attrition factors (failure due to unreliability and failure due to battle damage) and logistic delays, which affect repair process. We develop a simulation model considering the fighter aircraft as the weapon system for arriving at transient solutions for availability with logistic delays. The methodology is based on discrete event simulation using Monte Carlo techniques. The failure time distribution (Weibull) for different subsystems, repair time distribution (exponential) and logistic delay time distribution (lognormal) were chosen with suitable parameters. The results indicate the pronounced decrease in availability (to as low as 20% in some cases) due to logistic delays. The results are however sensitive to the reliability, maintainability and logistic delay parameters.