Circular Economy, Recycling & Remanufacturing worked example

Reuse Inventory Days with daily reuse demand or withdrawals of 73 units / day: a worked example

Suppose daily reuse demand or withdrawals falls to 73 units / day. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate required inventory for reusable parts, returnable packaging, or refurbished units based on daily demand and loop lead time.

The inputs for this scenario

  • Daily reuse demand or withdrawals: 73 units / day (the input this scenario stresses; the baseline uses 145)
  • Reuse loop replenishment lead time: 12 days (held at the documented default)
  • Safety stock for return variability and quality holds: 420 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Loop cycle stock = daily reuse demand or withdrawals × reuse loop replenishment lead time.
  • Protected days of supply works out to 0.01 units at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 6.08 days at these inputs.
  • Inventory works out to 73 pieces at these inputs.
  • Daily usage works out to 12 pieces / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where daily reuse demand or withdrawals sits at 145 units / day and the headline result is 0.03 units, this scenario comes in 49.66% below the baseline at 0.01 units.
  • It computes required loop inventory as cycle stock — daily reuse demand times replenishment lead time — plus a safety stock for return variability and quality holds. 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

  • Protected days of supply: 0.01 units (headline result)
  • Unprotected days: 6.08 days
  • Inventory: 73 pieces
  • Daily usage: 12 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Reuse Inventory Days calculator, set daily reuse demand or withdrawals to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.