Maintenance & Reliability worked example

Spare Parts Carrying Cost at 13% annual carrying rate: a worked example in maintenance & reliability

Suppose annual carrying rate falls to 13%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate annual carrying cost for maintenance spares from average inventory value, carrying rate, and fixed storage burden.

The inputs for this scenario

  • Average spare inventory value: 450,000 $ (held at the documented default)
  • Annual carrying rate: 13 % (the input this scenario stresses; the baseline uses 18)
  • Carrying capture factor: 100 % (held at the documented default)
  • Fixed storage and administration cost: 12,000 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Variable carrying cost = average spare inventory value × annual carrying rate × carrying capture factor.
  • Annual Spare Carrying Cost works out to 5,862,000 $ / yr at these inputs, and this is the headline figure for the scenario.
  • Carrying Cost per Inventory Dollar works out to 13.03 $ / $ at these inputs.
  • Variable Carrying Cost works out to 5,850,000 $ at these inputs.
  • Fixed Storage Burden works out to 12,000 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where annual carrying rate sits at 18% and the headline result is 8,112,000 $ / yr, this scenario comes in 27.74% below the baseline at 5,862,000 $ / yr.
  • It multiplies average spare inventory value by the annual carrying rate and a capture factor to get variable carrying cost, then adds fixed storage and administration to give total annual carrying cost. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Annual Spare Carrying Cost: 5,862,000 $ / yr (headline result)
  • Carrying Cost per Inventory Dollar: 13.03 $ / $
  • Variable Carrying Cost: 5,850,000 $
  • Fixed Storage Burden: 12,000 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Spare Parts Carrying Cost calculator, set annual carrying rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.