Inventory Fill Rate
Inventory fill rate is the percentage of requested spare-parts demand supplied immediately from available stock.
What this term means in maintenance
Inventory fill rate is the percentage of requested spare-parts demand supplied immediately from available stock.
Formula
Fill rate = Demand supplied immediately ÷ Total valid demand × 100
Practical example
A store receives requests for 500 units and supplies 460 immediately.
Fill rate = 92%
Unit and line measures
Fill rate may use requested units, order lines, or complete orders. The basis should be stated.
Criticality
A high overall fill rate can still hide poor availability of critical spares.
Data requirements
Accurate requests, issues, backorders, substitutions, and stock balances are needed.
Common mistake
Counting an approved substitute as filled without confirming technical acceptance can overstate performance.
How this term differs
Inventory Fill Rate is the proportion of requested demand supplied immediately from stock. It is related to Stockout Rate, Spare Parts Service Level, and Stock Accuracy, but these terms describe different records, measures, roles, strategies, or decisions and should not be used interchangeably.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Spare Parts Service Level
Spare parts service level measures how reliably maintenance inventory can meet valid parts demand when required.
Stockout Rate
Stockout rate is the percentage of valid spare-parts requests that cannot be supplied from available stock when required.
Stock Accuracy
Stock accuracy is the degree to which recorded inventory quantities and locations match the physical spare parts actually available.
Glossary FAQs
- What is inventory fill rate?
The percentage of valid demand supplied immediately from available stock.
- Can fill rate use units or order lines?
Yes. The calculation basis must be stated.
- Why separate critical items?
A high overall rate can hide missing critical spares.