NPI, DFM/DFA & Engineering Change worked example

Launch Inventory Buffer with on-hand launch inventory of 600 units: a worked example in npi, dfm/dfa & engineering change

This worked example runs the launch inventory buffer numbers for a tougher week than the baseline: on-hand launch inventory of 600 units instead of the typical 1,200 units. Estimate launch inventory buffer for npi, dfm/dfa and engineering change using production-ready inputs so teams can plan replenishment and safety stock using actual usage and lead time.

The inputs for this scenario

  • On-hand launch inventory: 600 units (the input this scenario stresses; the baseline uses 1,200)
  • Forecast daily usage at launch: 85 units / day (held at the documented default)
  • Launch safety-stock factor: 1.1 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Launch inventory buffer cycle stock = launch inventory buffer daily usage × launch inventory buffer 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 on-hand launch inventory sits at 1,200 units and the headline result is 12.83 days, this scenario comes in 50% below the baseline at 6.42 days.
  • Use it when setting and monitoring inventory buffers during a new-product launch and ramp. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

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 Launch Inventory Buffer calculator, set on-hand launch inventory to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.