Quality worked example

Defect Rate with defects found of 45 defects: a worked example

This scenario runs the defect rate calculation on the strong side: defects found of 45 defects, with every other input held at its documented default. Use when quality performance needs a normalized metric.

The inputs for this scenario

  • Defects found: 45 defects (raised for this scenario; the documented default is 18)
  • Units inspected: 5,000 units (unchanged)
  • Defect opportunities per unit: 4 opp / unit (unchanged)

Working through the calculation

  • Applying the documented formula (Defect rate = defects รท units inspected) to the inputs above produces each figure below.
  • At this operating point the engine returns 9,000 PPM for defects ppm, the number this scenario is built around.
  • At this operating point the engine returns 0.9 % for defect rate.
  • At this operating point the engine returns 2,250 DPMO for dpmo.
  • At this operating point the engine returns 99.1 % for quality rate.

How this compares with the baseline

  • Against the tool's baseline example, where defects found sits at 18 defects and the headline result is 3,600 PPM, this scenario comes in 150% above the baseline at 9,000 PPM.
  • Use it when reporting line or supplier quality on a scorecard, converting an internal reject count into a customer-facing PPM number, or estimating sigma level from a defect opportunity model. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Defects PPM: 9,000 PPM (headline result)
  • Defect rate: 0.9 %
  • DPMO: 2,250 DPMO
  • Quality rate: 99.1 %

Run it with your numbers

  • Every input above is editable in the live Defect Rate calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.