Patent ID: 8000930

Claim:
A method for monitoring a degradable system, suffering from a plurality of faults (F i ), comprising: a) providing, for each fault (F i ), a propagation parameter (τ i ) characteristic of a system type, wherein the propagation parameter (τ i ) is a degradation rate or a time constant; b) providing, for each fault (F i ), a distribution of symptom values (p(δ|F i ), p(δ| F )) characteristic of the system type; c) providing operation and maintenance data (t maint ) of the system wherein the maintenance data (t maint ) comprises a time since a prior maintenance or overhaul action; d) calculating, by a digital computing device, for each fault (F i ) and based on the propagation parameter (τ i ) from step a) and the operation and maintenance data (t maint ) from step c), a pre-symptom fault probability (P(F i )) of the system; and e) computing, by the digital computing device, for each fault (F i ) and based on the distribution of symptom values (p(δ|F i ), p(δ| F )) from step b) and the pre-symptom fault probability (P(F i )) from step d), a symptom-conditional fault probability P(F i |δ) of the system.