Question: How can you tell whether your PM program is effective? Is there a PM deficiency standard percentage?
Jerry, maintenance planner, Nebraska
Answer: Jerry, I'm not aware of a standardized PM deficiency rating to target to gauge whether your PM program is effective. That said, there are indicators that will reflect that information. Some of these indicators are readly apparent; others may require a little sleuthing activity to undercover.
Let's dissect the PM program, for starters. Through the use of various approaches, some based on criticality and others on the bleeding, we need to have defined our proactive maintenance strategies. These include condition-based tasks to find equipment in the act of failure, time-based scheduled restoration or discard tasks, and failure-finding tasks to detect hidden failures. Of course, no scheduled maintenance is an option, too.
The first step in determining a PM program's value is to identify the level of reactivity in the organization. Is every day a new day, with equipment constantly failing and production struggling to meet target numbers? Asset availability is a good indicator of PM effectiveness.
Next, look at the PM tasks. Do the PMs address the assets' likely failure modes? If not, then we are wasting a lot of time executing PMs that consume resources but don’t add value. PMs of this nature also mean that you are heavily dependent on the resources you use to execute the PMs correctly having the skills and knowledge needed to accomplish the work. That is becoming a much harder task for many organizations.
Remember that most PMs should be inspections that are focused on finding equipment in the act of failure, i.e. the P-F curve. If the craftspeople are fixing everything on the PM and not generating corrective work orders, there is most likely very little backlog to plan and schedule. This lack of corrective work impedes proactive work management and drives down the levels of craft efficiency achievable. Intrusive PMs can increase the level of self-induced failures by disturbing otherwise stable assets.
We can also look at the condition monitoring or PdM program effectiveness. You might have PdM technologies in place but a poor work management process. Data comes in from the technologies, but no one acts on the findings to prevent equipment's demise. The same concepts apply to operators taking process readings and where no action is taken when corrective work notifications are entered into the system.
PM compliance is another indicator of PM effectiveness. If we are placing PMs on the schedule (assuming that they add value) and the work is deferred, then PM compliance is lower. While we want 100% done, we target a PM compliance of 95%.
If you measure rework as a metric, then that is an indicator of PM effectiveness as well. With rework, we often see intrusive PMs executed and failures happening on the equipment that recently underwent PM activities.
Finally, high maintenance costs are another indicator of poor PM performance. High levels of PM activities (especially the wrong types of PMs) and constant failure result in higher maintenance expense.
What other insights might you have on this topic that did I not mention? Send me an email at the address below and I will respond or place your questions with my answers here.
Please post your comments so everyone can all learn.
Jeff Shiver, CMRP
If you have problems in the fields of maintenance, reliability, planning and scheduling, MRO storerooms, or leadership as examples, please contact Jeff Shiver with your question(s) here.