Machine Vision & Industrial Inspection AI worked example

Vision Defect Detection Rate at 99% required detection rate specification: a worked example

Push required detection rate specification up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when validating a vision system against a known-defect sample set and you need to calculate detection rate and compare it to your system specification or customer requirement.

The inputs for this scenario

  • Defects correctly detected by vision system: 94 defects (unchanged)
  • Total actual defects in validation sample: 100 defects (unchanged)
  • Required detection rate specification: 99 % (raised for this scenario; the documented default is 98)

Working through the calculation

  • Applying the documented formula (Defect detection rate = defects detected / total actual defects x 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 94 % for defect detection rate, the number this scenario is built around.
  • At this operating point the engine returns 5 points for gap to detection specification.
  • At this operating point the engine returns 94 count for defects correctly detected.
  • At this operating point the engine returns 100 count for total actual defects in sample.

How this compares with the baseline

  • Against the tool's baseline example, where required detection rate specification sits at 98% and the headline result is 94 %, this scenario lands almost exactly on the baseline at 94 %.
  • It computes the percentage of known defects the vision system correctly detected and the point gap to your required detection specification. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Defect detection rate: 94 % (headline result)
  • Gap to detection specification: 5 points
  • Defects correctly detected: 94 count
  • Total actual defects in sample: 100 count

Run it with your numbers

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

Last reviewed 2026-05-12.