Supply Chain & Procurement worked example
Days of Supply with current inventory on hand of 11,300 units: a worked example
Push current inventory on hand up to 11,300 units and the picture changes. This example computes every intermediate figure at that operating point. Use it when days of supply in supply chain and procurement is being sized for a buffer or safety stock review.
The inputs for this scenario
- Current inventory on hand: 11,300 units (raised for this scenario; the documented default is 4,500)
- Average daily demand: 300 units / day (unchanged)
- Coverage safety factor: 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 current 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.
- It computes how many days of demand your on-hand inventory covers, both at face value and after derating by a safety multiplier. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.
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 Days of Supply calculator, which recalculates instantly and can be shared with the inputs intact.
Last reviewed 2026-05-12.