This indicator examines the root causes of breakdowns and then investigates whether the root cause should have been detected as part of the preventive maintenance program. This provides an evaluation of the effectiveness of the preventive maintenance task and also the thoroughness of the individual carrying out the task. For example, lubrication-related failures should not occur on equipment that is inspected and lubricated as part of the preventive maintenance program. The breakdown indicates a failure of the preventive maintenance program. Modifications to the task listing, the retraining of an individual, or the addition of some visual control technique may be required to insure there is no repetition of the failure.
Breakdowns Caused by Items that should have been
Inspected, Serviced, or a Part of the PM Program
Total Number of Breakdowns
Expressed as a percentage
The formula indicates that the total number of breakdowns that could have been prevented or detected by the preventive maintenance pro-gram is compared to the total number of breakdowns. The resulting percentage indicates the opportunity for improvement for upgrading or changing the preventive maintenance program. An additional driver for improvement can be uncovered if the losses (maintenance costs, equipment damage, downtime costs) incurred by the breakdowns are also included.
This indicator is beneficial to any organization desiring to improve their preventive maintenance program. It provides an accurate insight into the effect that preventive maintenance is having on the equipment break-downs. Monitoring this indicator helps to insure that the preventive maintenance policy is cost effective.
The greatest weakness to using this indicator is procedural. In other words, the organization must be committed to completing accurate and detailed root cause analysis of equipment breakdowns. If the root cause is merely assumed or guessed, then the true effectiveness of the preventive maintenance program is obscured.
Tip from Maintenance Strategy Series Volume 1 - Preventive Maintenance by Terry Wireman