Hydrogen Electrolyzer & Fuel Cell Manufacturing worked example

Stack Assembly Yield at 68% target first-pass stack assembly yield: a worked example

This worked example runs the stack assembly yield numbers for a tougher week than the baseline: 68% target first-pass stack assembly yield instead of the typical 95%. Estimate first-pass stack assembly yield for PEM, alkaline, SOEC, PEMFC, or SOFC stacks by comparing built stacks that pass leak, voltage, and torque checks against the total stacks attempted on the line.

The inputs for this scenario

  • Stacks passing first-time leak, torque, and voltage checks: 232 stacks (held at the documented default)
  • Total stacks attempted in the same period: 250 stacks (held at the documented default)
  • Target first-pass stack assembly yield: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: First-pass stack assembly yield = stacks passing first-time ÷ total stacks attempted × 100.
  • First-pass stack assembly yield works out to 92.8 % at these inputs, and this is the headline figure for the scenario.
  • Yield gap to target works out to -24.8 points at these inputs.
  • Stacks passing first-time works out to 232 count at these inputs.
  • Total stacks attempted works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target first-pass stack assembly yield sits at 95% and the headline result is 92.8 %, this scenario lands almost exactly on the baseline at 92.8 %.
  • Use it for daily or shift-level line reporting during a stack assembly ramp, or to quantify how far a cell is from its yield commitment. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • First-pass stack assembly yield: 92.8 % (headline result)
  • Yield gap to target: -24.8 points
  • Stacks passing first-time: 232 count
  • Total stacks attempted: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Stack Assembly Yield calculator, set target first-pass stack assembly yield to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.