Supply Chain & Procurement worked example

Resilience Buffer Calculator with inventory on hand of 11,300 units: a worked example

What does the result look like when inventory on hand reaches 11,300 units? The full calculation is worked below with real intermediate numbers. Use it when resilience buffer in supply chain and procurement is being sized for a buffer or safety stock review.

The inputs for this scenario

  • Inventory on hand: 11,300 units (raised for this scenario; the documented default is 4,500)
  • Average daily consumption: 300 units / day (unchanged)
  • Disruption safety multiplier: 1.2 x (unchanged)

Working through the calculation

  • Applying the documented formula (Protected days = inventory on hand ÷ daily usage ÷ safety multiplier) to the inputs above produces each figure below.
  • At this operating point the engine returns 31.39 days for protected days of supply, the number this scenario is built around.
  • At this operating point the engine returns 37.67 days for unprotected days.
  • At this operating point the engine returns 11,300 pieces for inventory.
  • At this operating point the engine returns 300 pieces / day for daily usage.

How this compares with the baseline

  • Against the tool's baseline example, where inventory on hand sits at 4,500 units and the headline result is 12.5 days, this scenario comes in 151% above the baseline at 31.39 days.
  • A figure at this level is achievable when inventory on hand is genuinely sustained, not just peaked for a shift. It assumes steady daily usage; if demand is lumpy or seasonal, protected days can be overstated because a single high-consumption day burns buffer faster than the average implies.

Results at a glance

  • Protected days of supply: 31.39 days (headline result)
  • Unprotected days: 37.67 days
  • Inventory: 11,300 pieces
  • Daily usage: 300 pieces / day

Run it with your numbers

  • Every input above is editable in the live Resilience Buffer Calculator calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.