Misconceptions about PM

Let's open our eyes


Here are some prevalent misconceptions about preventive maintenance.

1. PM is only a way of trying to determine when and what will break or wear out so you can replace it before it does.

Yes PM does that. But PM is much bigger then that. It is an integrated approach to managing budgets and failure analysis and eliminating excessive resource use and permanent correction of problem areas.

PM can actually be seen as a way of life.

More than half of the PM effort is directed toward postponing or eliminating the failure. When you tighten a loose bolt you postpone or eliminate that bolt coming off and causing a failure.

2. PM systems are all the same. You can just copy the system from the manual or from your old job and it will work.

PM systems must be designed for the actual equipment as set-up, age of the equipment, product, type of service, hours of operation, skill of operators and many other factors.

Since at least some of the PM effort is wasted, it behooves us to look closely at what we are doing so as to waste as little as possible. By not customizing the system you could be programming in unnecessary labor for the next five years.

3. PM is extra work on top of existing workloads, and it costs more money.

Yes and No. PM is an extra effort. The payoff may be in another budget.

PM increases uptime, reduces energy usage, reduces unplanned events, reduces rental bills, lodging, meals and a bunch of other non-maintenance costs. There are hundreds of ways PM saves an organization resources.

The only time PM adds massively to the existing workload is at the startup when you put a PM system into place.

You will be doing PM and still having breakdowns. You will have to spend extra to fund monies not invested into the equipment in the past (pay for past sins).

This may have to go on for awhile before you catch up.

4. With good forms and descriptions, unskilled people can do PM tasks.

PM is two-sided. Unskilled technicians can do some of the PM tasks successfully with good training and clear forms.

TLC activities (such as lubrication, cleaning or tightening bolts) can certainly be done by a trained, but not necessarily fully-qualified, mechanic.

Inspection is another story. The other part of PM is the issue.

How long does it take to train someone to walk under a unit and know when something is amiss? How long before their ears are tuned to hear problems?

For the greatest return on investment, skilled people must be in the loop. Inspection benefits greatly from experienced eyes and hands.

5. PM is a series of task lists and inspection forms to be applied at specific intervals, and is now obsolete because of all the new high-tech equipment.

Motor vehicles wear out and it is essential to catch the deterioration before failure hurts someone or causes additional excessive damage. The OEMs study their equipment failures and warranty claims and design their PMs to reduce failures.

A good PM is an intelligent one.

Technology is changing the business. All predictive maintenance activity is part of preventive maintenance. That includes the most modern approaches, including vibration routes, Infrared surveys or condition-based maintenance checks.

The newest PM strategies initiate activity on some condition - such as initiate task list when temperature gauge reads 220°F, and are also part of PM.

6. PM will eliminate all breakdowns.

In the words of a PM master: "PM can't put iron into a machine." In other words, the equipment must be able to do the job. PM cannot make a 5-ton dump truck do the work of a 10-ton one.

Even with the most advanced PM there will still be breakdowns from abuse, misapplication or accident. Some failure modes do not currently lend themselves to PM approaches (such as electronics failures) or truly random failures (such as stones breaking windshields).

Of course breakdowns due to operators are not addressed by PM activity - at least proactively.

This is a small attempt to enter the world of PM with our eyes open.

This content continues onto the next page...

We Recommend