A system that characterizes degradation of a component in a system. During operation, the system monitors inferential variables associated with a specimen of the component. Next, the system determines a time for the onset of degradation for the specimen and determines a time for the completion of degradation for the specimen. The system then computes a time interval between the onset of degradation and the completion of degradation, and uses the time interval to look up an entry in a defect library to obtain information which characterizes the degradation of the specimen of the component.