Machine Vision & Industrial Inspection AI worked example

False Reject Cost at 2.88% false reject rate: a worked example

This scenario runs the false reject cost calculation on the strong side: 2.88% false reject rate, with every other input held at its documented default. Use it when optimizing pass-fail thresholds or camera parameters and you need to quantify what over-sensitivity is costing in scrapped or reworked good parts each month.

The inputs for this scenario

  • Monthly production volume inspected: 50,000 parts / month (unchanged)
  • Cost per falsely rejected good part: 4.8 $ / part (unchanged)
  • False reject rate (good parts wrongly rejected): 2.88 % (raised for this scenario; the documented default is 2.5)
  • Fixed monthly sorting and containment cost: 800 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Monthly false rejects = monthly production volume x false reject rate / 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 7,712 $ for total monthly false reject cost, the number this scenario is built around.
  • At this operating point the engine returns 0.15 $ / piece for false reject cost per inspected part.
  • At this operating point the engine returns 6,912 $ for variable false reject cost.
  • At this operating point the engine returns 800 $ for fixed sorting and containment cost.

How this compares with the baseline

  • Against the tool's baseline example, where false reject rate sits at 2.5% and the headline result is 6,800 $, this scenario comes in 13.41% above the baseline at 7,712 $.
  • Use it when tuning inspection thresholds, evaluating a new vision setup, or chasing an unexplained scrap spike. 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

  • Total monthly false reject cost: 7,712 $ (headline result)
  • False reject cost per inspected part: 0.15 $ / piece
  • Variable false reject cost: 6,912 $
  • Fixed sorting and containment cost: 800 $

Run it with your numbers

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

Last reviewed 2026-05-12.