Quality & Metrology worked example

Defects Per Unit with total defects found during inspection of 45 defects: a worked example

This scenario runs the defects per unit calculation on the strong side: total defects found during inspection of 45 defects, with every other input held at its documented default. Use it to track defect levels over time and to feed first-pass yield, DPMO, and Six Sigma reporting.

The inputs for this scenario

  • Total defects found during inspection: 45 defects (raised for this scenario; the documented default is 18)
  • Units inspected in the sample: 400 units (unchanged)
  • Reporting conversion factor (e.g. per 100): 1 x (unchanged)

Working through the calculation

  • Applying the documented formula (Defects per unit = defects found รท units inspected) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.11 defects / unit for defects per unit, the number this scenario is built around.
  • At this operating point the engine returns 0.11 value for raw ratio.
  • At this operating point the engine returns 1 x for conversion factor.
  • At this operating point the engine returns 400 value for units inspected.

How this compares with the baseline

  • Against the tool's baseline example, where total defects found during inspection sits at 18 defects and the headline result is 0.05 defects / unit, this scenario comes in 150% above the baseline at 0.11 defects / unit.
  • Use it when you have counted every defect (not just rejected units) across an inspection lot and need a normalized rate for trending, DPMO conversion, or process comparison. 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 per unit: 0.11 defects / unit (headline result)
  • Raw ratio: 0.11 value
  • Conversion factor: 1 x
  • Units inspected: 400 value

Run it with your numbers

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

Last reviewed 2026-05-12.