Tooling, Fixtures, Dies & Mold Economics worked example

Spare Tooling Inventory with spare tooling daily usage of 600 units / day: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop spare tooling daily usage to 600 units / day, then walk the calculation through step by step. Estimate spare tooling inventory for tooling, fixtures, dies and mold economics using production-ready inputs so teams can plan replenishment and safety stock using actual usage and lead time.

The inputs for this scenario

  • Spare tooling daily usage: 600 units / day (the input this scenario stresses; the baseline uses 1,200)
  • Replenishment lead time: 85 days (held at the documented default)
  • Safety stock multiplier: 1.1 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Spare tooling inventory cycle stock = spare tooling inventory daily usage × spare tooling inventory lead time.
  • Protected days of supply works out to 6.42 days at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 7.06 days at these inputs.
  • Inventory works out to 600 pieces at these inputs.
  • Daily usage works out to 85 pieces / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where spare tooling daily usage sits at 1,200 units / day and the headline result is 12.83 days, this scenario comes in 50% below the baseline at 6.42 days.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to spare tooling daily usage, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes steady daily usage and a stable lead time; demand spikes from a rush job or a supplier delay will erode the protected days faster than the model shows.

Results at a glance

  • Protected days of supply: 6.42 days (headline result)
  • Unprotected days: 7.06 days
  • Inventory: 600 pieces
  • Daily usage: 85 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Spare Tooling Inventory calculator, set spare tooling daily usage to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.