Diagnostic apparatus

A diagnostic apparatus for diagnosing a symptom of an anomaly in a device configured to perform an operation for making or breaking a circuit, the apparatus comprising:

• a processor encoded with program code for diagnosing a symptom of an anomaly in a device, when executed the program code configuring the processor to:
• receive data associated with the device, the data measuring an operational state of the device;
• calculate a factor probability for each matter that may be a factor in a symptom observed in the device based on the received data, the factor probability being a probability that the matter truly corresponds to a factor for the observed symptom;
• and
• data storage circuitry configured to store:
• verification data being data verified for each of symptoms that may occur in the device, the verification data representing probabilities that two or more matters that may be factors for the symptoms truly correspond to the factors for the symptoms, respectively;
• and
• history information representing a history of maintenance to which the device has been subjected;
• the processor being further configured by the program code to:
• generate details of a proposal for improving the observed symptom, based on calculation results of the factor probabilities,
• calculate the factor probabilities by correcting the verification data on the symptom observed in the device, based on a current state of the device determined from the history information,
• the details of the proposal determined by the improvement processing unit include items and adjustment rates, the items being proposed to be adjusted for improving a symptom, the adjustment rates representing an adjustment balance for each item in a combination of the items, and
• the adjustment rates are obtained based on a track record of improving a symptom in the device stored in the data storage circuitry.