Supply Chain & Procurement worked example

Supplier Quality PPM with nonconforming parts rejected of 30 parts: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop nonconforming parts rejected to 30 parts, then walk the calculation through step by step. Score supplier quality for Supply Chain & Procurement in parts-per-million from defective and total parts.

The inputs for this scenario

  • Nonconforming parts rejected: 30 parts (the input this scenario stresses; the baseline uses 60)
  • Total parts received from supplier: 150,000 parts (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Quality PPM = defective parts ÷ total parts × 1,000,000.
  • Quality PPM works out to 200 PPM at these inputs, and this is the headline figure for the scenario.
  • Defect rate works out to 0.02 % at these inputs.
  • Defective parts works out to 30 parts at these inputs.
  • Total parts works out to 150,000 parts at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where nonconforming parts rejected sits at 60 parts and the headline result is 400 PPM, this scenario comes in 50% below the baseline at 200 PPM.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to nonconforming parts rejected, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. PPM only reflects the parts you actually inspected and rejected; if incoming inspection is sample-based rather than 100%, escaped defects and unreported field returns are invisible to this number.

Results at a glance

  • Quality PPM: 200 PPM (headline result)
  • Defect rate: 0.02 %
  • Defective parts: 30 parts
  • Total parts: 150,000 parts

Run it with your numbers

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

Last reviewed 2026-05-12.