Circular Economy, Recycling & Remanufacturing worked example

Closed-Loop Inventory Days with daily closed-loop consumption of 110 units / day: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop daily closed-loop consumption to 110 units / day, then walk the calculation through step by step. Estimate inventory needed to keep a closed-loop material, core, packaging, or reusable-component flow supplied.

The inputs for this scenario

  • Daily closed-loop consumption: 110 units / day (the input this scenario stresses; the baseline uses 210)
  • Return, inspection, repair, or replenishment lead time: 9 days (held at the documented default)
  • Closed-loop safety stock: 500 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Loop cycle stock = daily closed-loop consumption × return, inspection, repair, or replenishment lead time.
  • Protected days of supply works out to 0.02 units at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 12.22 days at these inputs.
  • Inventory works out to 110 pieces at these inputs.
  • Daily usage works out to 9 pieces / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where daily closed-loop consumption sits at 210 units / day and the headline result is 0.05 units, this scenario comes in 47.62% below the baseline at 0.02 units.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to daily closed-loop consumption, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes steady daily consumption and a stable loop lead time; demand spikes or variable refurbish times need extra buffer beyond the simple safety-stock term.

Results at a glance

  • Protected days of supply: 0.02 units (headline result)
  • Unprotected days: 12.22 days
  • Inventory: 110 pieces
  • Daily usage: 9 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Closed-Loop Inventory Days calculator, set daily closed-loop consumption to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.