Rare Earth Magnet & Motor Materials worked example

Inventory Coverage with magnet consumption per day of 3,000 units / day: a worked example in rare earth magnet & motor materials

This scenario runs the inventory coverage calculation on the strong side: magnet consumption per day of 3,000 units / day, with every other input held at its documented default. Use it when inventory coverage in rare earth magnet and motor materials is being sized for a buffer or safety stock review.

The inputs for this scenario

  • Magnet consumption per day: 3,000 units / day (raised for this scenario; the documented default is 1,200)
  • Supplier replenishment lead time: 85 days (unchanged)
  • Safety stock multiplier: 1.1 units (unchanged)

Working through the calculation

  • Applying the documented formula (Inventory coverage cycle stock = inventory coverage daily usage × inventory coverage lead time) to the inputs above produces each figure below.
  • At this operating point the engine returns 32.09 days for protected days of supply, the number this scenario is built around.
  • At this operating point the engine returns 35.29 days for unprotected days.
  • At this operating point the engine returns 3,000 pieces for inventory.
  • At this operating point the engine returns 85 pieces / day for daily usage.

How this compares with the baseline

  • Against the tool's baseline example, where magnet consumption per day sits at 1,200 units / day and the headline result is 12.83 days, this scenario comes in 150% above the baseline at 32.09 days.
  • Use it when setting reorder points or reviewing exposure on long-lead, single-source rare earth magnet inventory. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Protected days of supply: 32.09 days (headline result)
  • Unprotected days: 35.29 days
  • Inventory: 3,000 pieces
  • Daily usage: 85 pieces / day

Run it with your numbers

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

Last reviewed 2026-05-12.