Definition
A critical spare is a spare part identified, typically through asset criticality assessment, as one whose unavailability at the moment of need would cause severe production, safety, or cost consequences (long lead time, no substitute, or protecting a highly critical asset) justifying dedicated stock even if it is used rarely and ties up capital.
Key facts
- Distinguished from an ordinary spare part by the severity of consequence if unavailable, not by physical difference.
- Often characterized by long procurement lead time, no viable substitute, or protecting a very high-criticality asset.
- Justifies inventory investment despite low or unpredictable usage frequency, unlike routine, fast-moving spares.
- Identification typically flows from asset criticality assessment applied down to the specific parts protecting that asset.
What information does Critical spare preserve?
A spare part is designated critical when the consequence of not having it available (extended downtime on a highly critical asset, a long replacement lead time, no available substitute) would be severe enough to justify holding dedicated stock, even though the part itself may rarely be needed.
How do maintenance teams use Critical spare?
Asset criticality assessment identifies which assets matter most; critical-spare designation extends that judgment down to the specific parts protecting those assets. A spare parts catalog then needs to flag which entries are critical, so stocking decisions and fill-rate targets can be set more conservatively for those items than for routine parts.
FAQ
Frequently asked questions
When is a spare part particularly critical to operations?
When its unavailability at the moment of need would cause severe downtime, safety, or cost consequences (due to long lead time, no substitute, or protecting a highly critical asset) justifying dedicated stock despite low usage.
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