Patent ID: 7246039

Claim:
A fault diagnosis system for diagnosing faults in complex equipment, the system including: means for storing a set of diagnostic signatures which relates a set of known faults which may occur in the equipment to respective fault symptoms which are deemed indicative of said known faults; and means for processing said diagnostic signatures and a set of fault symptoms identified for a current state of the equipment, to calculate diagnostic data for identifying a fault causing the current state of the equipment, the diagnostic data including a plurality of values which are indicative of different relative non-zero likelihoods of each of a plurality of different known faults causing the current state of the equipment, wherein said diagnostic signatures relate the set of known faults which may occur in the equipment to respective fault symptoms which are deemed unrelated to said known faults, and wherein the system is arranged to calculate the diagnostic data such that a fault symptom being present in said current state symptoms and being deemed indicative of a known fault in said diagnostic signatures provides a more positive contribution to a value indicative of likelihood of the corresponding fault being causative, than a different fault symptom being present in said current state symptoms and being deemed unrelated to the fault in said diagnostic signatures.