There is no single best maintenance strategy
Preventive maintenance replaces, restores, or inspects equipment on a schedule. Predictive maintenance uses condition or performance information to identify when intervention is needed. Both can be effective, and both can be wasteful when applied without understanding the failure mode.
When preventive maintenance makes sense
Time-based work is a good fit when age or usage changes the probability of failure, the useful life is understood, and the task can restore the expected function. Examples can include scheduled replacement of wear components, calibration, cleaning, or inspections with clear acceptance criteria.
When predictive maintenance makes sense
Condition-based work is a good fit when the failure develops through a detectable warning period and the organization can collect, interpret, and act on the signal. Vibration, thermography, oil analysis, ultrasound, electrical testing, and performance trending can all be useful depending on the asset and failure mode.
Questions that prevent over-maintenance
- What failure are we trying to prevent or detect?
- What is the consequence if it occurs?
- Is there a detectable condition before functional failure?
- How much warning time is available?
- Can the team respond before the consequence occurs?
- Would redesign, redundancy, or run-to-failure be more appropriate?
Measure the strategy, not just compliance
PM completion is important, but it does not prove that a task is effective. Review repeat failures, emergency work, false alarms, avoided failures, condition-monitoring findings, and the labor and material cost of the program. Retire or revise tasks that do not change risk.
Use these decisions as part of a broader reliability improvement program, and download the GTEK Industrial downtime guide for a practical starting sequence.