Also called PM, planned maintenance, scheduled maintenance
What is preventive maintenance?
Servicing equipment on a fixed schedule, by elapsed time or cycle count, whatever its condition.
What else it is called
- Other names
- PM, planned maintenance, scheduled maintenance
- In French
- maintenance préventive
Related entries
Understanding preventive maintenance
Work carried out on a schedule rather than in response to a condition. Lubrication, filter changes, belt replacement and inspection all happen at set intervals regardless of how the machine looks, on the reasoning that a planned stop is far cheaper than an unplanned one.
Its weakness is that intervals are set conservatively, so components get replaced with useful life remaining. That waste is usually worth accepting, because the alternative is either monitoring equipment you have to buy and maintain, or failures you did not plan for.
The decision worth making explicitly is which machines get this, which get condition monitoring, and which are simply run until they fail. A three-hundred-dollar pump with a spare on the shelf does not justify either a schedule or a sensor.
In practice
Check whether your intervals have ever been revised against failure history. Most plants set them from the manual at installation and never look again, in either direction.
Frequently asked
How do we set the interval?
Start from the manufacturer’s recommendation, then adjust using your own failure history and duty cycle. A machine running three shifts in a dusty environment needs shorter intervals than the manual assumes, and a lightly used one needs longer.