Covers measures for the detection of faults (monitoring the occurrence of a fault), fault localisation (finding the cause of the fault) and fault indication (i.e. providing information on the cause of the fault).
Fault detection is normally undertaken by an operator or a maintenance specialist. In the majority of cases mostly very accurate knowledge of the functional sequences is required for this purpose. In addition, fault detection costs time and money. For this reason the demand for automatic fault detection and diagnostic systems is increasing.