Preventive vs. Predictive Maintenance
Quick answer: Preventive maintenance services equipment on a fixed schedule (every so many hours, cycles, or months) to prevent failures. Predictive maintenance watches the equipment's actual condition -- vibration, temperature, oil analysis -- and services it only when the data says it's needed. Predictive avoids both surprise breakdowns and unnecessary service, but requires sensors and analysis.
The Three Strategies
| Strategy | Trigger | Trade-off |
|---|---|---|
| Reactive (run-to-failure) | Fix it after it breaks | Cheapest to start, most costly in downtime and damage |
| Preventive | A time or usage schedule | Prevents many failures, but can over-service good parts |
| Predictive | The asset's real condition | Most efficient, but needs sensors, data, and skills |
Preventive Maintenance
Preventive is the workhorse: scheduled inspections, lubrication, and part replacement based on time or usage. It's simple and dramatically better than waiting for failures. The downside is that it sometimes replaces parts that still had life left, or misses failures that don't follow the schedule.
Predictive Maintenance
Predictive uses condition monitoring -- vibration analysis, thermography, oil analysis, ultrasonic testing -- to detect wear before it becomes failure. You service the asset right when it needs it: not too early, not too late. It delivers the best uptime and lowest total cost, but requires instrumentation and the skills to interpret the data.
How to Choose
Match the strategy to the asset. Run-to-failure can be fine for cheap, non-critical, redundant equipment. Use preventive as your baseline for most assets. Reserve predictive for critical, expensive, or hard-to-replace equipment where downtime is costly. This mix is the backbone of a strong TPM program.
Frequently Asked Questions
Is predictive always better?
Not always -- it costs more to set up. For low-criticality assets, preventive or even run-to-failure can be the smarter economic choice.
How does this relate to TPM?
TPM combines operator-led basic care with planned (preventive) and predictive work, plus improvement teams. Preventive and predictive are the planned-maintenance engine inside TPM.
Build Maintenance Reliability with Vetted Safe
Vetted Safe's Maintenance library covers preventive and predictive maintenance, TPM, and troubleshooting -- assign by role and track every completion.