Glossary
PPM (Planned Preventive Maintenance)
Plain-Language Definition
Scheduled maintenance activities performed at regular intervals to prevent equipment failure, extend asset life, and maintain safety compliance — as opposed to reactive maintenance performed after a breakdown occurs.
Technical Context
PPM schedules are derived from: manufacturer recommendations (e.g., chiller service every 6 months), regulatory requirements (e.g., fire system testing monthly per NFPA 25), industry standards (e.g., ASHRAE 180 for HVAC), and operational experience. PPM compliance rate = (completed PPM tasks / scheduled PPM tasks) x 100. Industry target: >95%. The reactive-to-planned maintenance ratio should be <20:80 — meaning less than 20% of all maintenance is unplanned. Common PPM tasks: filter changes (monthly-quarterly), belt inspection (quarterly), bearing lubrication (quarterly-annually), full system inspection (annually), major overhaul (3-5 year cycle).
Why It Matters
Reactive maintenance costs 3-5 times more than planned maintenance due to emergency labour rates, expedited parts, collateral damage, and business disruption. Regular PPM extends equipment life by 25-50%, maintains warranty validity, and provides documented evidence of maintenance for insurance and compliance.
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