Supplier Quality, Development & Audits worked example

Supplier Defect PPM with defective units rejected of 23 units: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop defective units rejected to 23 units, then walk the calculation through step by step. Convert supplier defects into parts-per-million for Supplier Quality, Development & Audits so quality can be scored on a common scale.

The inputs for this scenario

  • Defective units rejected: 23 units (the input this scenario stresses; the baseline uses 45)
  • Total units received: 120,000 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Defect PPM = defective units ÷ total units received × 1,000,000.
  • Defect PPM works out to 192 PPM at these inputs, and this is the headline figure for the scenario.
  • Defect rate works out to 0.02 % at these inputs.
  • Defective units works out to 23 units at these inputs.
  • Total units works out to 120,000 units at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where defective units rejected sits at 45 units and the headline result is 375 PPM, this scenario comes in 48.89% below the baseline at 192 PPM.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to defective units rejected, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. PPM only counts defects you detected - escapes that slip past receiving inspection are invisible, so a low PPM can reflect weak detection rather than a truly clean supplier.

Results at a glance

  • Defect PPM: 192 PPM (headline result)
  • Defect rate: 0.02 %
  • Defective units: 23 units
  • Total units: 120,000 units

Run it with your numbers

  • To rerun this with your own numbers, open the live Supplier Defect PPM calculator, set defective units rejected to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.