Lean Manufacturing & Operations worked example

WIP Days of Supply with current wip level of 500 units: a worked example

This scenario runs the wip days of supply calculation on the strong side: current wip level of 500 units, with every other input held at its documented default. Use this calculator to translate WIP counts into days, making it easier to communicate lead time impact, set reduction targets, and track lean progress.

The inputs for this scenario

  • Current WIP level: 500 units (raised for this scenario; the documented default is 200)
  • Daily throughput: 50 units/day (unchanged)
  • Unit conversion factor: 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (WIP Days = Current WIP / Daily Throughput x Conversion Factor) to the inputs above produces each figure below.
  • At this operating point the engine returns 10 days for wip days of supply, the number this scenario is built around.
  • At this operating point the engine returns 10 value for raw ratio.
  • At this operating point the engine returns 1 x for conversion factor.
  • At this operating point the engine returns 50 value for daily throughput.

How this compares with the baseline

  • Against the tool's baseline example, where current wip level sits at 200 units and the headline result is 4 days, this scenario comes in 150% above the baseline at 10 days.
  • Use it when sizing buffers, diagnosing lengthening lead times, or communicating WIP levels to non-technical stakeholders in days rather than units. 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

  • WIP days of supply: 10 days (headline result)
  • Raw ratio: 10 value
  • Conversion factor: 1 x
  • Daily throughput: 50 value

Run it with your numbers

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

Last reviewed 2026-05-12.