Industrial Minerals & Powder Processing worked example

Silo Inventory Days with daily draw-down rate of 23 tons / day: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop daily draw-down rate to 23 tons / day, then walk the calculation through step by step. Calculate how many days of production or shipment a mineral storage silo can cover based on usable capacity, current inventory, and daily draw-down rate.

The inputs for this scenario

  • Daily draw-down rate: 23 tons / day (the input this scenario stresses; the baseline uses 45)
  • Current silo inventory: 320 tons (held at the documented default)
  • Safety stock buffer: 3 days (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Days of supply = current silo inventory / daily draw-down rate.
  • Protected days of supply works out to 0.02 days at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 0.07 days at these inputs.
  • Inventory works out to 23 pieces at these inputs.
  • Daily usage works out to 320 pieces / day at these inputs.

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 48.89% below the baseline at 0.02 days.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to daily draw-down rate, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. 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: 0.02 days (headline result)
  • Unprotected days: 0.07 days
  • Inventory: 23 pieces
  • Daily usage: 320 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Silo Inventory Days calculator, set daily draw-down rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.