Second, using case studies, this project is empirically investigating the hypothesis that testability is a valid model component for reliability prediction. Testability is defined as the probability that a set of tests will discover a fault given that one exists. Measuring testability implies estimating the joint probability of these events occurring given an input. This is a computation intensive process. The system consists of an E-8 aircraft with a multimode radar system and mobile ground stations.
Computer systems are both in the aircraft and on the ground.
The system performs ground surveillance, providing real time detection, location, classification, and tracking of moving and fixed objects. During Operation Desert Storm in 1991, two prototypes were pressed into service. Tactical military software is required to have high reliability. Under the spiral life cycle model, identifying fault-prone modules early in an iteration can lead to a more reliable prototype. High reliability of each iteration translates into a highly reliable final product.