Abnormality diagnosis method, abnormality diagnosis apparatus, and non-transitory computer recording medium

An abnormality diagnosis method of diagnosing, with an abnormality diagnosis apparatus, abnormality of a braking unit included in a prescribed apparatus, the prescribed apparatus including:

• the braking unit including a pressing member, an urging member that urges the pressing member toward an actuator, and an attraction device that releases an urging state of the pressing member that is pressed by the urging member;
• and a controller configured to control braking by the braking unit, the prescribed apparatus being configured to change operation programs each including a plurality of operation steps, the abnormality diagnosis method comprising:
• calculating, by the abnormality diagnosis apparatus, an attraction time period when the prescribed apparatus executes prescribed operation steps associated with corresponding operation programs, the attraction time period being a period of time during which the attraction device attracts the pressing member;
• diagnosing, by the abnormality diagnosis apparatus, abnormality of the braking unit based on the calculated attraction time period
• calculating, by the abnormality diagnosis apparatus, the attraction time period when each of the operation steps in each of the operation programs is executed;
• calculating, by the abnormality diagnosis apparatus, an evaluation value for evaluating accuracy of the calculated attraction time period;
• and
• associating, by the abnormality diagnosis apparatus, as the prescribed operation step, the operation step highest in evaluation value, among calculated evaluation values in each of the operation steps included in each of the operation programs, with the corresponding operation program.