Preventive Maintenance
Servicing equipment on a schedule so it does not fail unexpectedly.
Quick Answer
Preventive maintenance is the practice of servicing building equipment and systems at planned intervals, based on time or usage, to reduce the chance of unexpected failure. Typical tasks include inspections, lubrication, filter changes, and calibration. It trades predictable routine cost for fewer emergency repairs and longer equipment life.
The Full Picture
Preventive maintenance sits between two other strategies. Reactive maintenance, or run-to-failure, waits for equipment to break and then fixes it. Predictive maintenance monitors equipment condition and intervenes when data suggests a problem is developing. Preventive maintenance is the scheduled middle ground: perform defined tasks at fixed intervals whether or not anything appears wrong.
A preventive maintenance program usually starts with an inventory of assets and the manufacturer's recommended service tasks and intervals, which are found in operation and maintenance manuals. Tasks are assigned frequencies such as monthly, quarterly, or annually, and are generated as work orders, commonly by a CMMS. Technicians complete the checklist and record findings so that trends and recurring problems become visible.
The tradeoff is that fixed schedules can over-maintain healthy equipment or miss problems that develop between visits. Facilities teams therefore tend to blend strategies, using preventive schedules for most assets, reactive handling for low-criticality items, and condition-based or predictive methods for expensive or critical equipment. Life-safety systems such as fire alarms and sprinklers also carry code-driven inspection requirements that function as mandatory preventive tasks.
For construction teams, preventive maintenance connects to closeout. Maintenance manuals, equipment lists, and warranty terms delivered at turnover are the raw material for the owner's program, and some warranties require documented routine maintenance to stay valid.
Real Examples
Common Misconceptions
People assume: Preventive maintenance and predictive maintenance are the same.
Actually: Preventive work follows a fixed calendar or usage interval. Predictive work is triggered by measured equipment condition, such as vibration or temperature trends.
People assume: More frequent maintenance is always better.
Actually: Excess servicing wastes labor and can introduce errors. Good programs set intervals from manufacturer guidance, failure history, and how critical the asset is.
Frequently Asked Questions
What is the difference between preventive and reactive maintenance?
Preventive maintenance is planned service done on a schedule to avoid failures. Reactive maintenance is repair performed after something breaks.
How often should preventive maintenance be done?
It depends on the equipment, manufacturer recommendations, operating conditions, and code requirements. Intervals commonly range from monthly checks to annual inspections, and are adjusted based on history.
What are examples of preventive maintenance tasks?
Replacing filters, lubricating moving parts, inspecting belts and electrical connections, testing emergency generators, cleaning coils, and checking safety devices are common examples.
How do you build a preventive maintenance program?
Inventory the assets, gather manufacturer maintenance requirements, assign tasks and frequencies, prioritize by criticality, and track completion and results, often using a CMMS. Review and adjust the program regularly using failure data.