Practical considerations in systems diagnosis using timed failure propagation graph models

Timed failure propagation graphs (TFPG) are causal models that capture the temporal aspects of failure propagation in dynamic systems. In this paper we present several practical modeling and reasoning considerations that have been addressed based on experience with avionics systems. These include the problem of intermittent faults, handling test alarms, dealing with limited computational resources, and model reduction for large scale systems.