- The care and servicing by personnel for the purpose of maintaining equipment and facilities in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or before they develop into major defects. Maintenance, including tests, measurements, adjustments, and parts replacement, performed specifically to prevent faults from occurring.
While preventive maintenance is generally considered to be worthwhile, it is important to note that there are risks such as equipment failure or human error involved when performing PM, just as in any maintenance operation. PM is also sometimes augmented by Reliability Centered Maintenance, which attempts to determine the best PM tasks, and by predictive maintenance, which models past behavior to predict failures.
To make it simple:
- Preventive maintenance is conducted to keep equipment working and/or extend the life of the equipment.
- Corrective maintenance, sometimes called "repair", is conducted to get equipment working again.
The primary goal of preventive maintenance is to prevent the failure of equipment before it actually occurs. It is designed to preserve and enhance equipment reliability by replacing worn components before they actually fail. Preventive maintenance activities include equipment checks, partial or complete overhauls at specified periods, oil changes, lubrication and so on. In addition, workers can record equipment deterioration so they know to replace or repair worn parts before they cause system failure. The ideal preventive maintenance program would prevent all equipment failure before it occurs.