Electronics Manufacturing worked example

First Pass Test Yield at 70% target first-pass test yield: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop target first-pass test yield to 70%, then walk the calculation through step by step. Measure first-pass test yield for PCB assemblies or electronic products against a target yield.

The inputs for this scenario

  • Units passing first-pass test: 1,110 assemblies (held at the documented default)
  • Total units tested: 1,200 assemblies (held at the documented default)
  • Target first-pass test yield: 70 % (the input this scenario stresses; the baseline uses 97)

Working through the calculation

  • The calculation starts from the formula this tool documents: First-pass test yield = units passing first-pass test ÷ total units tested.
  • First-pass test yield works out to 92.5 % yield at these inputs, and this is the headline figure for the scenario.
  • Yield gap to target works out to -22.5 points at these inputs.
  • Units passing first-pass test works out to 1,110 assemblies at these inputs.
  • Total units tested works out to 1,200 assemblies at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target first-pass test yield sits at 97% and the headline result is 92.5 % yield, this scenario lands almost exactly on the baseline at 92.5 % yield.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to target first-pass test yield, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. FPY counts a unit as failed even if it later passes after rework, so a high FPY tells you nothing about whether failures are repairable — track rework yield separately.

Results at a glance

  • First-pass test yield: 92.5 % yield (headline result)
  • Yield gap to target: -22.5 points
  • Units passing first-pass test: 1,110 assemblies
  • Total units tested: 1,200 assemblies

Run it with your numbers

  • To rerun this with your own numbers, open the live First Pass Test Yield calculator, set target first-pass test yield to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.