Preventive maintenance is routine, scheduled upkeep performed on assets to reduce the chance of failure before it happens.
Preventive maintenance is routine, scheduled upkeep performed on an asset before anything has failed - servicing, inspection, lubrication, calibration, parts replacement - to reduce the chance of breakdown. It is the planned counterpart to corrective maintenance, which responds to faults after they appear: preventive work happens because the calendar or the odometer says so, not because something is wrong.
How preventive schedules are triggered
- Time-based - work recurs on the calendar: quarterly filter changes, annual portable appliance testing, six-monthly harness inspections. Simple to run, and the only option where regulations fix the interval.
- Usage-based - work recurs on a meter: oil changes by mileage on company vehicles, servicing by engine hours on plant, blade changes by cycle count. Better matched to actual wear, but it requires someone to read and record the meter.
- Event-based - work tied to moments rather than intervals: pre-season checks on seasonal kit, an inspection whenever hire equipment comes back, a once-over before a long deployment.
The intervals themselves come from manufacturer guidance, statutory inspection requirements, and the duty cycle the asset actually sees - a van doing site deliveries on rough access roads wears faster than the handbook assumes.
Preventive vs corrective vs predictive
The three approaches differ in what triggers the work. Preventive runs on a fixed schedule; corrective runs after a fault is found; predictive maintenance uses condition data - vibration, temperature, oil analysis - to time the work just before failure. Each has a cost profile. Preventive sometimes services parts that had life left in them. Corrective risks the failure happening mid-job, when downtime is most expensive. Predictive needs sensors and data most small fleets do not have. In practice, small and mid-size teams run preventive schedules on critical assets, accept corrective work on the rest, and track reliability with measures like MTBF where the records support it.
What a workable schedule looks like
The failure mode of preventive maintenance is rarely the wrench work - it is the schedule living in one person’s head or a forgotten spreadsheet tab. The habits that hold up: attach the interval to the asset itself, not to a generic to-do list; raise each due job as a work order with an owner and a date; log every completed job with who did it, what was replaced, and what it cost; and review intervals yearly against what actually broke. In AMPthilly, maintenance entries, warranty dates, and service history live on the asset record, with the audit trail keeping a permanent log of each completed job.
Why the paper trail matters as much as the work
Preventive maintenance done but not recorded buys less than it should. Warranty claims get rejected without evidence of servicing; resale buyers pay more for a machine with a documented history; insurers and auditors ask for inspection records on safety equipment, and “we definitely did it” is not a record. The maintenance log is also what tells you when to stop: an asset whose upkeep entries are stacking up faster than its remaining value is a replacement decision waiting to be read off the page.
Related terms
- Corrective Maintenance - repair work after a fault is found, the other half of most maintenance programmes
- Predictive Maintenance - condition data decides the timing instead of a fixed schedule
- MTBF - mean time between failures, the reliability measure preventive work aims to raise
- MTTR - mean time to repair, the downtime measure for when failures do happen
- Work Order - the unit of scheduled work a preventive plan generates