NPI, DFM/DFA & Engineering Change worked example

Pre-Production Capacity at 99% expected pre-production capacity uptime: a worked example

What does the result look like when expected pre-production capacity uptime reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when pre-production capacity in npi, dfm/dfa and engineering change is being asked to take on more work and you need to know if there is room.

The inputs for this scenario

  • Pre-production capacity output per cycle: 4 units / cycle (unchanged)
  • Available pre-production capacity cycles: 480 cycles (unchanged)
  • Expected pre-production capacity uptime: 99 % (raised for this scenario; the documented default is 90)
  • Expected pre-production capacity first-pass yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross pre-production capacity = pre-production capacity output per cycle × available pre-production capacity cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good pre-production capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross pre-production capacity.
  • At this operating point the engine returns 19.2 units for pre-production capacity downtime loss.
  • At this operating point the engine returns 57.02 units for pre-production capacity yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where expected pre-production capacity uptime sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • A figure at this level is achievable when expected pre-production capacity uptime is genuinely sustained, not just peaked for a shift. Uptime and first-pass yield during ramp are estimates that improve as the process stabilizes, so early runs of the calculator should use conservative, learning-curve-adjusted figures.

Results at a glance

  • Good pre-production capacity: 1,844 units (headline result)
  • Gross pre-production capacity: 1,920 units
  • Pre-production capacity downtime loss: 19.2 units
  • Pre-production capacity yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Pre-Production Capacity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.