Definition
Spare parts fill rate measures the percentage of spare-parts requests that can be fulfilled immediately from stock on hand, as opposed to requiring a procurement delay. A low fill rate directly extends repair time and drags down measures like first-time fix rate and MTTR, making it a key input to overall maintenance responsiveness.
Key facts
- Measures immediate stock availability against demand: a request delayed by procurement counts as a miss, not a fill.
- Directly influences MTTR and first-time fix rate: a missing part extends repair time and can force a return visit.
- Balancing fill rate against inventory carrying cost is a core trade-off in spare-parts stocking policy.
- Typically tracked per part category or criticality tier, since not all parts warrant the same stocking investment.
How is Spare parts fill rate calculated?
Spare parts fill rate is calculated by tracking, for each spare-parts request or work order requiring a part, whether that part was available immediately from stock, then dividing the number of immediately fulfilled requests by the total number of requests over a period.
What influences Spare parts fill rate?
A part not on the shelf when needed directly extends repair time, whether through a rush order or waiting for standard delivery, which is why fill rate is closely linked to MTTR and first-time fix rate: a low fill rate can undermine gains made elsewhere in diagnosis speed or technician skill.
FAQ
Frequently asked questions
How often can spare-parts demand be met from available supply?
The spare parts fill rate measures it: the percentage of spare-parts requests that can be fulfilled immediately from stock on hand, without a procurement delay.
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