Treating everything the same means shortchanging what matters
No maintenance team has an unlimited budget, unlimited headcount, or 48-hour days. Yet an organization that has never ranked its equipment often ends up giving every asset the same level of attention: the same systematic preventive plan on a secondary conveyor as on the line that carries 80% of production. The result is over-maintaining machines whose failure has no real consequence, and under-maintaining the ones that can shut the plant down or hurt someone.
Criticality analysis answers a simple question: where should you concentrate your maintenance effort to get the best return? It is not about finding extra resources, but about spending the resources you already have intelligently.
The principle of criticality analysis
Ranking an asset by criticality means assessing the real impact of a failure, setting probability aside at first. You typically look at four dimensions:
- Safety and environment: can a failure injure an operator, cause a leak, a fire, a discharge?
- Production: is the asset a bottleneck? Is there a workaround, a redundant unit, a buffer stock?
- Quality: can a drift produce scrap, non-conformities, a customer recall?
- Cost: the direct repair cost, but also downtime cost, late penalties, overtime.
Crossing these criteria produces a hierarchy: critical, important, and secondary assets. A simple “severity × probability” matrix is often enough to surface the ranking. The goal is not scientific precision but a shared, defensible team decision.
FMEA: breaking the failure apart
FMEA (Failure Mode and Effects Analysis), known in French as AMDEC, goes one step further than simply ranking assets. It drills down to the level of the failure mode: for a given asset, you list the ways it can fail, and for each one you analyze:
- the failure mode: seized bearing, drifting sensor, broken belt, leaking seal;
- the effect: what the process or user experiences (stoppage, slowdown, non-conformity, hazard);
- the cause: wear, insufficient lubrication, contamination, overload.
The criticality of each mode is then scored, classically, as the product of three factors:
Criticality = Severity × Occurrence × Detection (the Risk Priority Number, or RPN)
- Severity measures how serious the effect is.
- Occurrence estimates how often the cause appears.
- Detection rates your ability to catch the problem before it produces its effect — a high score means you barely see it coming.
The product gives a priority index that lets you sort failure modes and focus action on those that combine high severity, high frequency, and low detectability. The detection score matters a great deal: a severe but well-detected mode (caught by a round or a sensor) is less urgent than a severe mode that strikes without warning.
Linking criticality to maintenance strategy
Ranking only has value if it drives concrete decisions. Criticality should guide the choice of maintenance policy for each asset:
- Critical assets: reinforced preventive maintenance and, where relevant, condition-based maintenance (vibration, temperature, oil analysis) or even predictive approaches. You want to anticipate the failure rather than suffer it.
- Important assets: calendar- or usage-based preventive maintenance, calibrated without excess, with spare parts on hand.
- Secondary assets: deliberate run-to-failure is often the rational choice. Repairing after a breakdown costs less than endlessly maintaining low-stakes equipment.
This graduated logic is developed in our article on maintenance types. Criticality is the thread that ties the analysis to your preventive maintenance plan: it tells you not only what to monitor, but how intensively.
A realistic way to get started
Don’t aim for an exhaustive FMEA of the whole fleet in the first month — that is the surest way to never finish. A progressive approach works better:
- Inventory your assets and group the fleet by line or by function.
- Quickly rate the criticality of each asset on a simple scale (say 1 to 3, or critical / important / secondary), bringing maintenance, production, and safety around the same table.
- Go deeper with FMEA only on the assets flagged as critical: that is where fine-grained failure-mode analysis pays off most.
- Translate into plans: define or adjust preventive work on the critical assets, lighten it on the secondary ones.
- Review: criticality is not fixed. It evolves with the fleet, with incidents, and with experience.
Starting simple and iterating beats a perfect analysis that never gets implemented.
Where a CMMS helps (and where it doesn’t)
Let’s be clear: Maint Vision is not a dedicated FMEA tool, and criticality analysis remains first and foremost a methodology carried by your teams. A CMMS does not replace the thinking about failure modes.
Once the analysis is done, however, the tool helps make it operational: Maint Vision lets you record a criticality level per asset and tailor preventive maintenance accordingly, instead of applying the same template everywhere. Reports then help you spot the assets that weigh the most — those concentrating the interventions, downtime, or costs — which in turn feeds the review of your ranking. Criticality stops being a forgotten spreadsheet and becomes a living criterion, visible on each asset’s record and in your indicators.
Concentrating maintenance where it counts is not a software matter but a matter of owning your priorities. A CMMS simply helps you hold those priorities over time.