Preventive Maintenance (PM) — definition
Planned maintenance programme performed at predetermined intervals or usage thresholds to reduce the probability of unplanned equipment failure.
Preventive maintenance contrasts with reactive (run-to-failure) and predictive (condition-based) approaches, and most industrial plants operate a blend of all three depending on asset criticality. Programmes are usually defined by the equipment manufacturer's recommended service intervals and adjusted using plant operating history.
Why it matters to industrial buyers
A documented preventive maintenance plan affects warranty compliance, insurance terms and the accuracy of mean time between failures projections used in feasibility studies.
Key reference points
Basis
Typically driven by calendar time, operating hours or production cycles.
Cost trade-off
Over-maintenance increases direct cost; under-maintenance increases failure risk and unplanned downtime.
Commonly confused with
Predictive maintenance
Predictive maintenance uses condition monitoring data to trigger work only when degradation is detected, rather than on a fixed schedule.
How it is used in practice
The maintenance contract specified quarterly preventive maintenance visits for the refrigeration compressors during the warranty period.
Frequently asked questions
Does preventive maintenance eliminate breakdowns?
No, it reduces failure probability but cannot eliminate all unplanned failures, particularly from random component defects.
Who typically performs it?
Either in-house maintenance teams, the equipment supplier under a service contract, or a specialised third party.
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Related terms
Mean Time Between Failures (MTBF)
Average operating time expected between one failure of a repairable system and the next, used as a reliability indicator for equipment and components.
Spare Parts Strategy
Planned approach to identifying, stocking and sourcing replacement components based on criticality, lead time and failure risk to limit unplanned downtime.
Commissioning
Systematic process of testing, adjusting and verifying that installed equipment and systems operate together as designed before handover to operations.
Capacity Utilisation
Percentage of a facility's or line's maximum theoretical production capacity that is actually used over a given period, reflecting demand, scheduling and reliability constraints.
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Reference content only. Global B2B Group is independent of equipment manufacturers and financing institutions; definitions are provided for education and do not constitute engineering, financial or legal advice.