The 4 types of equipment maintenance, with examples
Reactive, preventive, predictive, and condition-based maintenance explained with shop-floor examples — and the realistic mix for a small operation.
Maintenance strategies sort by one question: what triggers the work? Four answers, four types.
1. Reactive (run-to-failure)
Trigger: it broke. The forklift stops lifting; now it’s maintenance. Reactive isn’t always wrong — it’s the rational strategy for cheap, non-critical, easily-replaced items. Nobody schedules preventive care for a $40 angle grinder; you stock a spare. Reactive becomes a problem when it’s the default for machines that stop production, because failures schedule themselves at the worst price: downtime, rush parts, overtime.
Right for: cheap tools with spares on the shelf. Wrong for: anything on the critical path.
2. Preventive (scheduled)
Trigger: the calendar or the hour meter. Blades every 90 days, compressor oil every 500 hours. Preventive maintenance trades a little over-servicing for predictability — failures get caught as line items on a Tuesday instead of emergencies on a deadline. It’s cheap to run (a schedule plus discipline) and it’s where every small shop should start.
Right for: the machines that stop work when they stop. Which is to say: most of them.
3. Predictive (data-driven)
Trigger: measured condition trends. Vibration analysis, oil sampling, thermal imaging — instrumentation watches wear develop and calls the service before failure. Powerful, and priced like it: sensors, monitoring, and someone who trusts the data. See preventive vs predictive for the full comparison.
Right for: expensive, failure-critical rotating equipment. Overkill for: the bandsaw.
4. Condition-based (inspected)
Trigger: a human looked. The middle path — no sensors, but no blind calendar either. Inspections on a schedule; work orders when the inspection finds something. Brake pads at 3mm get replaced; at 8mm they get logged. Condition-based rides on two habits: honest inspections and a written history so trends are visible.
Right for: wear parts with visible degradation — belts, pads, hoses, tires, blades.
The realistic mix for a small shop
| Equipment | Strategy |
|---|---|
| Critical machines (saws, compressors, CNC, vehicles) | Preventive, hour-based where meters exist |
| Wear components on those machines | Condition-based via scheduled inspection |
| Cheap tools with spares | Reactive, unapologetically |
| The one machine that would end the month | Preventive now; predictive when scale justifies it |
The mix matters less than the bookkeeping: every strategy degenerates into reactive if due work doesn’t surface and completions don’t get logged. That surfacing-and-logging layer is precisely what maintenance management software does — the strategy stays yours.