The maintenance strategies, and when each one applies.
Planned, preventive, corrective, predictive, reliability-centred, emergency — they are not competing products. They are levels, and a serious plant runs several at once on different equipment.
The main types
Planned maintenance
Any work scheduled in advance rather than triggered by a failure. The umbrella the others sit under.
Preventive — PM
Activities performed to stop a failure occurring: inspection, servicing, tightening, balancing, lubrication, part replacement.
Corrective — CM
Work aimed at the root cause so the same failure does not recur, then extended across every machine in that equipment family.
Predictive — PdM
Condition-based: oil analysis, thermography, vibration and noise measurement, thickness testing, motor current analysis.
Reliability-centred — RCM
Strategy chosen per asset according to its failure modes and consequences, rather than one interval for everything.
Emergency — EM
Work after the machine has already stopped. Every plant tries to eliminate it, because it means production stopped.
What corrective maintenance actually involves
When equipment fails, three separate things have to happen. First, containment: stop the failure spreading to other equipment or components. That can be as simple as shutting the machine down, or as involved as adjusting feed and isolating valves in a petrochemical unit.
Second, restoration: replace the failed parts, repair the machine, return it to working condition and hand it back to production. This is the step most people mean by repair.
Third — and this is the one most often skipped — root cause failure analysis. Why did this happen? The output of that analysis is a corrective action, and a corrective action is only worth the name if it stops the failure recurring and is applied across the whole equipment family, not just the one machine.
Total Productive Maintenance (TPM)
TPM is the Japanese maintenance management system, built on eight pillars: 5S workplace organisation, planned maintenance, autonomous (operator) maintenance, kaizen, training, quality, safety and environment, and administrative TPM.
Its central concern is controlling and eliminating losses, and its main measure is OEE — Overall Equipment Effectiveness. If you are choosing a direction for a plant with a mature maintenance function, this is usually it.
Choosing a strategy for your plant
Do not apply one level to everything
The most frequent mistake in large organisations is a single strategy for all equipment. Critical assets and minor ones need different treatment.
Start from the business model
A power plant is paid for availability. Below 95% readiness it not only loses revenue but incurs penalties — so its strategy is time-driven.
Start from the business model
A component manufacturer with fixed orders competes on production cost, so its maintenance strategy is cost-driven. Same modules, different KPIs.
Not sure which strategy fits your equipment?
Tell us your industry and your critical assets and we will talk it through honestly.
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