NPI, DFM/DFA & Engineering Change worked example

Prototype Scrap Cost at 61% unrecoverable share of value: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop unrecoverable share of value to 61%, then walk the calculation through step by step. Estimate the cost of scrapped prototypes from scrap count, value lost per piece, the unrecoverable share, and disposal cost.

The inputs for this scenario

  • Prototypes scrapped: 15 parts (held at the documented default)
  • Value lost per scrapped prototype: 110 $ / part (held at the documented default)
  • Unrecoverable share of value: 61 % (the input this scenario stresses; the baseline uses 85)
  • Disposal and handling cost: 250 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total prototype scrap cost = scrapped prototypes × value lost per scrap × unrecoverable share + disposal and handling cost.
  • Total prototype scrap cost works out to 1,257 $ at these inputs, and this is the headline figure for the scenario.
  • Prototype scrap cost per unit works out to 83.77 $ / piece at these inputs.
  • Variable prototype scrap cost works out to 1,007 $ at these inputs.
  • Fixed prototype scrap cost adder works out to 250 $ at these inputs.

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 23.96% below the baseline at 1,257 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to unrecoverable share of value, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. 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: 1,257 $ (headline result)
  • Prototype scrap cost per unit: 83.77 $ / piece
  • Variable prototype scrap cost: 1,007 $
  • Fixed prototype scrap cost adder: 250 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Prototype Scrap Cost calculator, set unrecoverable share of value to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.