30 days' grace? Sorry, not so with a PM

ask jeff shiver 30 days grace Not with a PMQuestion: Jeff, in one of your presentations, you discussed the PM compliance metric and applying the 10% rule. Can you elaborate on that?

Mike, maintenance coordinator, Georgia

Answer: Mike, we want to focus on the business objectives we are trying to accomplish and the behaviors we want to drive by using metrics. Remember that the PM (PM/PdM) program coupled with operator basic care is how we break the reactive cycle. The PMs should be designed to address likely failure modes and to do so at the right frequency. Also, PMs should be detailed at the appropriate level using precision maintenance techniques.

The goals of the PM program are.

  1. Find things in the act of failure – a condition-monitoring approach
  2. Perform scheduled restoration or discard the asset based on asset life regardless of condition
  3. Conduct failure-finding activities for hidden and protective devices.

PM compliance simply refers to (PM and PdM work orders completed by their due) date divided by (the PM and PdM work orders due) using the 10% rule. With loans and credit-card payments, there is a 30-day grace period. If the payment was due on the first day of the month, then you have a 30-day grace period to pay. It seems like we try to apply that same logic with PMs, too. We cannot use that concept in maintenance. Let me explain.

Too many organizations approach a 30-day PM as having a 30-day window to complete the work, and here's what happens. The PM triggers on the first day of the month; the technician completes it on the third day of the month. On the first day of the following month, the PM triggers again. The technician holds the work until the 29th day of the month. Now, the interval between work actions has been nearly 60 days. If we can wait 60 days, then why not change the frequency of the PM from 30 to 60 days? To add insult to injury, the PM triggers on the first of the following month and the system technician is on vacation, so another technician completes the PM on the third day of the month. Now it has been only five days since the work was last done.

Applying the 10% rule, if the PM is triggered every 30 days, then the PM should be completed +/- 3 days of when it was due. The goal of the 10% rule is to keep our PM intervals consistent. That said, there has to be balance because of constraints outside our control. On a 30-day PM frequency, I look for completion in the currently scheduled week, which gives a little more flexibility but applies a time to execute constraint. Using the 10% rule is easier if we have completed workload leveling of PMs based on resource availability.

There are numerous metrics an organization can use to track maintenance and reliability performance.  To that end, the Society of Maintenance and Reliability Professionals (SMRP.org) has a vast library of metrics available to its membership or for purchase.

What is your experience with the PM compliance metric? Do you apply the 10% rule? What can we do differently? Please comment on your thoughts below. Any questions?

Talk soon,
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.