NPI, DFM/DFA & Engineering Change worked example

Design Change Payback with engineering change implementation cost of 62,500 $: a worked example

This scenario runs the design change payback calculation on the strong side: engineering change implementation cost of 62,500 $, with every other input held at its documented default. Use it when design change payback in npi, dfm/dfa and engineering change is being put in front of a capital committee and the savings story needs to hold up.

The inputs for this scenario

  • Engineering change implementation cost: 62,500 $ (raised for this scenario; the documented default is 25,000)
  • Annual savings from the design change: 18,000 $ / yr (unchanged)
  • Annual cost to sustain the change: 2,500 $ / yr (unchanged)

Working through the calculation

  • Applying the documented formula (Net annual design change payback savings = annual design change payback savings - annual design change payback support cost) to the inputs above produces each figure below.
  • At this operating point the engine returns 4.03 yr for design change payback payback period, the number this scenario is built around.
  • At this operating point the engine returns 15,500 $ / yr for net annual design change payback savings.
  • At this operating point the engine returns 62,500 $ for design change payback investment.
  • At this operating point the engine returns 15,000 $ for five-year net design change payback value.

How this compares with the baseline

  • Against the tool's baseline example, where engineering change implementation cost sits at 25,000 $ and the headline result is 1.61 yr, this scenario comes in 150% above the baseline at 4.03 yr.
  • Use it when ranking competing ECNs or building the business case for a cost-reduction or yield-improvement change before committing tooling and validation spend. 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

  • Design change payback payback period: 4.03 yr (headline result)
  • Net annual design change payback savings: 15,500 $ / yr
  • Design change payback investment: 62,500 $
  • Five-year net design change payback value: 15,000 $

Run it with your numbers

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

Last reviewed 2026-05-12.