NPI, DFM/DFA & Engineering Change worked example

Prototype Scrap Cost at 98% unrecoverable share of value: a worked example

What does the result look like when unrecoverable share of value reaches 98%? The full calculation is worked below with real intermediate numbers. an NPI team needs to quantify scrap exposure from iterative prototype builds during development.

The inputs for this scenario

  • Prototypes scrapped: 15 parts (unchanged)
  • Value lost per scrapped prototype: 110 $ / part (unchanged)
  • Unrecoverable share of value: 98 % (raised for this scenario; the documented default is 85)
  • Disposal and handling cost: 250 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Total prototype scrap cost = scrapped prototypes × value lost per scrap × unrecoverable share + disposal and handling cost) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,867 $ for total prototype scrap cost, the number this scenario is built around.
  • At this operating point the engine returns 124 $ / piece for prototype scrap cost per unit.
  • At this operating point the engine returns 1,617 $ for variable prototype scrap cost.
  • At this operating point the engine returns 250 $ for fixed prototype scrap cost adder.

How this compares with the baseline

  • Against the tool's baseline example, where unrecoverable share of value sits at 85% and the headline result is 1,653 $, this scenario comes in 12.98% above the baseline at 1,867 $.
  • A figure at this level is achievable when unrecoverable share of value is genuinely sustained, not just peaked for a shift. It assumes a single representative value per scrapped part; mixed lots with very different part values should be split and run separately for accuracy.

Results at a glance

  • Total prototype scrap cost: 1,867 $ (headline result)
  • Prototype scrap cost per unit: 124 $ / piece
  • Variable prototype scrap cost: 1,617 $
  • Fixed prototype scrap cost adder: 250 $

Run it with your numbers

  • Every input above is editable in the live Prototype Scrap Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.