Industrial Minerals & Powder Processing worked example

Silo Inventory Days with daily draw-down rate of 110 tons / day: a worked example

What does the result look like when daily draw-down rate reaches 110 tons / day? The full calculation is worked below with real intermediate numbers. Use it when an operations manager or logistics planner needs to schedule silo refills, plan truck or railcar deliveries, or set safety stock levels for ground limestone, calcium carbonate, silica, or other stored mineral products.

The inputs for this scenario

  • Daily draw-down rate: 110 tons / day (raised for this scenario; the documented default is 45)
  • Current silo inventory: 320 tons (unchanged)
  • Safety stock buffer: 3 days (unchanged)

Working through the calculation

  • Applying the documented formula (Days of supply = current silo inventory / daily draw-down rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.11 days for protected days of supply, the number this scenario is built around.
  • At this operating point the engine returns 0.34 days for unprotected days.
  • At this operating point the engine returns 110 pieces for inventory.
  • At this operating point the engine returns 320 pieces / day for daily usage.

How this compares with the baseline

  • Against the tool's baseline example, where daily draw-down rate sits at 45 tons / day and the headline result is 0.05 days, this scenario comes in 144% above the baseline at 0.11 days.
  • A figure at this level is achievable when daily draw-down rate is genuinely sustained, not just peaked for a shift. It assumes a constant draw-down rate; a sudden production ramp or a second shift will shorten real runway well below the calculated days.

Results at a glance

  • Protected days of supply: 0.11 days (headline result)
  • Unprotected days: 0.34 days
  • Inventory: 110 pieces
  • Daily usage: 320 pieces / day

Run it with your numbers

  • Every input above is editable in the live Silo Inventory Days calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.