A plurality of weak discriminators output determinations results about a status of an apparatus. Weight values are individually assigned to the determination results. By performing majority vote of the weighted determination results, the status of the apparatus is determined. The determination results are displayed on a single status indicating screen such that portions corresponding to a normal status are indicated in white while portions corresponding to an anomalous status are indicated in one or more colors other than white. The areas of the portions differ from one another depending on magnitudes of weight assigned to the determination results corresponding to the portions.