Decision theoretic troubleshooting of coherent systems

We present an approach to efficiently generating an inspection strategy for fault diagnosis. We extend the traditional troubleshooting framework to model nonperfect repair actions, and we include questions. Questions are troubleshooting steps that do not aim at repairing the device, but merely are performed to capture information about the failed equipment, and thereby ease the identification and repair of the fault. We show how Vesely and Fussell’s measure of component importance extends to this situation, and focus on its applicability to compare troubleshooting steps. We give an approximate algorithm for generating a “good” troubleshooting strategy in cases where the assumptions underlying Vesely and Fussell’s component importance are violated, and discuss how to incorporate questions into this troubleshooting strategy. Finally, we utilize certain properties of the domain to propose a fast calculation scheme.