A method to diagnosis an electro-mechanical part on an image forming device comprising: determining an incident count for a first time interval for the electro-mechanical part; determining a first threshold level for the first time interval; monitoring the electro-mechanical part for a second time interval, wherein the second time interval is a plurality of first time intervals; determining if the incident count for a first portion of the second time interval for the electro-mechanical part equal to or less than the first threshold; determining if the incident count for a second portion of the second time interval for the electro-mechanical part is equal to or less than the first threshold when the incident count for the first portion of the second time interval fails to exceed the first threshold for the electro-mechanical part; determining a maximum incident count for the second portion of the second time interval when the incident count for the second portion of the second time interval exceeds the first threshold for the electro-mechanical part; calculating an error ratio between an average incident count of the first portion of the second time interval and the maximum incident count of the second portion of the second time interval; and marking the electro-mechanical part as needing to be one of repaired or serviced when the error ratio exceeds an error ratio threshold level.