NPI, DFM/DFA & Engineering Change worked example

Part Count Reduction Savings at 54% share of theoretical savings actually captured: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop share of theoretical savings actually captured to 54%, then walk the calculation through step by step. Estimate net savings from a part-count reduction by valuing each eliminated component against the one-time redesign engineering cost.

The inputs for this scenario

  • Parts eliminated from the assembly: 8 parts (held at the documented default)
  • Fully-loaded annual cost carried per part: 6.5 $ / part (held at the documented default)
  • Share of theoretical savings actually captured: 54 % (the input this scenario stresses; the baseline uses 75)
  • One-time redesign engineering cost: -3,200 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Net savings = parts eliminated × cost carried per part × realized share − redesign engineering cost.
  • Total part count reduction savings cost works out to 28.08 $ at these inputs, and this is the headline figure for the scenario.
  • Part count reduction savings cost per unit works out to 3.51 $ / piece at these inputs.
  • Variable part count reduction savings cost works out to 28.08 $ at these inputs.
  • Fixed part count reduction savings adder works out to 0 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share of theoretical savings actually captured sits at 75% and the headline result is 39 $, this scenario comes in 28% below the baseline at 28.08 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to share of theoretical savings actually captured, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. The fully-loaded per-part carrying cost is an estimate; if you only count piece price you will badly understate the savings, and if you double-count overhead you will overstate it.

Results at a glance

  • Total part count reduction savings cost: 28.08 $ (headline result)
  • Part count reduction savings cost per unit: 3.51 $ / piece
  • Variable part count reduction savings cost: 28.08 $
  • Fixed part count reduction savings adder: 0 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Part Count Reduction Savings calculator, set share of theoretical savings actually captured to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.