What criticality is for
Asset criticality answers one question: if this machine fails, how much does it hurt? It drives decisions every maintenance team makes daily — which breakdown gets the next technician, which machines get preventive maintenance first, which spare parts are worth holding in stock. A plant without criticality makes those decisions anyway, just inconsistently and from memory.
How to rank a machine in practice
You do not need a consultant's matrix to start. Ask four questions about each machine:
- Production impact — does a failure stop the line, slow it, or nothing?
- Safety and environment — can a failure hurt someone or release something?
- Redundancy — is there a second machine that can take over?
- Recovery — how long and how expensive is a repair, and are the parts available?
Score the answers roughly and map them to a 1–5 scale. The value is not in the precision of the number; it is in the conversation that produces it, and in the fact that the answer is now written down.
An empty field is not zero
A blank criticality reads as “unimportant” to a sorting function and as “unknown” to a human, and those two readings do not survive contact with each other. Printing Not recorded instead of leaving a gap is a small thing that prevents a machine being quietly treated as low priority because nobody had got round to it.
Do not invent severity names for somebody else's scale
The tempting move is to label a 1–5 scale with words that sound authoritative: low, moderate, high, serious, critical. It reads better. It also asserts a grading scheme — and a machine's criticality is a plant's own judgement, not a software vendor's taxonomy.
So in UR Maintain the words are the plain ordinal reading of the number and nothing more: Lowest, Low, Medium, High, Highest. If your plant wants severity language, that is your vocabulary to define, and the number carries it faithfully.
Identity fields are the ones that pay back
Criticality is useful; maker, model and serial number are what you reach for when a part-finding exercise starts with “what is actually in this machine?”. All four are optional, all four read back as Not recorded when absent, and a manager or administrator can correct them from the machine's own page without a data-cleansing project. See why machine context matters for how those fields come together at the machine.
Start rough, improve where it matters
A rough ranking applied to your twenty most critical machines beats a precise ranking applied to none. Criticality is a decision aid, not an audit — and a system that lets you improve it a machine at a time will get there, while one that demands a complete dataset first will not.
A practical order:
- List the machines that stop the plant when they stop. Rank those first.
- Add the ones with safety or environmental risk.
- Leave the rest as Not recorded until a breakdown or a review gives you a reason to rank them.
- Revisit the ranking after a line change, a new machine or a run of failures.
An example ranking
A small packaging plant might end up with something like this for its first twenty machines:
- 5 — Highest: the filler that feeds every line, no redundancy, long repairs.
- 4 — High: the main conveyor and the palletiser — a stop halts output, but repairs are usually quick.
- 3 — Medium: labellers and checkweighers with a manual fallback.
- 2 — Low: the spare compressor that only runs when the main one is down.
- 1 — Lowest: workshop equipment that does not touch production.
The words are only the reading of the number; the reasons — no redundancy, long repairs, manual fallback — are what make the ranking useful, so write them down next to it.
Frequently asked questions
Who should set criticality? The people who live with the consequences: the maintenance manager together with production, and someone responsible for safety. A ranking made by one person in an office will be challenged on the first night shift.
How often should we review it? When something changes — a new line, a machine moved to a bottleneck, a run of failures — and otherwise once a year. Criticality is not permanent; it follows how the plant runs.
Should criticality drive breakdown priority automatically? It should inform it, not dictate it. A low-criticality machine with a safety issue still comes first.
How criticality connects to the rest
Once ranked, criticality should shape preventive-maintenance effort, spare-part stocking and breakdown priority. It also tells you where reliability figures like MTBF and MTTR are worth tracking closely — on the machines that matter most, not on every asset at once.
