As maintenance practitioners we often do our utmost best to try and prevent as many failures as possible. Afterall, failures create downtime… And downtime results in big profit losses for the organisation.
But sometimes, our fear of failures leads us to doing way more Preventive Maintenance tasks than necessary… resulting in highly inefficient and expensive PM programs. Here’s what I mean.
Imagine a leaking tank in your organisation. How worried would you be?
Well, that depends on what’s in the tank, where the tank is, and many more factors, right?
So let’s say we have 3 scenarios:
- It contains potable water with a minor pinhole leak.
- The water is used for firefighting purposes in a hazardous facility, and there is a severe leak
- The tank contained highly flammable liquid instead, and the leak is still quite severe.
In the first scenario, it’s not really a major problem. We could probably run with a minor leak of potable water for quite some time, right? In the second scenario, we’re definitely more concerned. That’s not something we want to deal with for too long, or if at all. In the third scenario, we’ve got a major issue at hand. Something we need to fix urgently pretty much immediately. This is also a scenario we would really want to avoid.
Do you see the difference? Not all failures are created equal. Some clearly matter more than others.
There are those so severe that they cost us millions of dollars… or even the lives of people. On the other hand, there are failures you wouldn’t care too much about if they happened. And since we are working with very limited resources… we need to allocate these scarce resources to failures that DO matter.
A good maintenance program does NOT try to prevent all failures. Good maintenance programs are risk based. They consider both the consequence and likelihood of failure… and assess where to use our scarce resources to get the greatest benefit. In fact, they are even prepared to deal with the consequences of accepting a certain level of failure.
In some cases, the impact of failure is so low, you must also consider the consequences of not doing anything. Because it might be more economical to let the failure run its course instead of doing the PM task.
Again, good maintenance programs are risk based. Sadly, most organisations are doing too many PMs. They are afraid to take risks. This creates PM programs that are highly expensive and inefficient, and full of tasks that don’t add value.
As John Moubray, the father of RCM II, pointed out in his book “Reliability Centered Maintenance”, typically between 40% – 60% of the PM tasks in a preventive maintenance program add little value.
Some of the most common problems are:
What’s worse is, we spend all that effort and resources on maintenance… yet still experience unacceptable failures.
- Tasks are duplicated.
- Tasks are done too frequently or not frequent enough
- Tasks are not effective at addressing the failure mode
- Too many fixed time, intrusive overhaul tasks that would be more effective, less costly and less disruptive to production if they were condition-based.
- Lack of using existing failure data and experience to set good task frequencies.
And the problem with our PM programs is that most of them were never developed properly, to begin with. But here’s the good news…
If you want to learn how to develop and improve your Preventive Maintenance Programs so you can identify non-value-adding tasks and either improve them or eliminate them.
Then this is for you.
In the coming weeks, we will be launching our NEW COURSE: PM100: Developing and Improving Preventive Maintenance Programs
Inside the course, we will delve deeper into each type of Preventive Maintenance…
I’ll discuss when to use each type… and how to implement them in your organisation.
Not only that…
The course focuses on teaching you the principles and practices you need to achieve higher reliability and availability whilst doing LESS maintenance.
Poor PM programs waste time and money, do not effectively address failures, and drive our organisations into a reactive, fire-fighting culture.
In the meantime, you can learn more about preventive maintenance by reading this article on the 9 Principles of a modern preventive maintenance program.