U.S. Department of Energy - Energy Efficiency and Renewable Energy
Federal Energy Management Program
Proper operations and maintenance (O&M) goes beyond repairing equipment after it breaks. Several maintenance strategies exist to prevent systems disrepair and degradation. A combination of the following can ensure an optimal blend of cost and life-cycle effectiveness:
Reactive Maintenance: Follows a "run it until it breaks" strategy. No action or effort is taken to maintain equipment, prevent failure, or ensure life of the system – even if actions are suggested by the manufacturer.
Preventive Maintenance: Refers to a series of actions performed on calendar time or machine run time schedules.
Predictive Maintenance: Strives to detect the onset of equipment degradation and address the problems as they are identified. Several predictive maintenance technologies exist.
Reliability-Centered Maintenance: Follows a process that addresses equipment conditions to determine maintenance requirements of any physical asset within its operating context.
Chapter 5 of the FEMP O&M Best Practices Guide outlines these maintenance types in detail. The full guide is also available.