Quality & Metrology worked example

Cost of Quality with prevention cost of 2,500 $: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop prevention cost to 2,500 $, then walk the calculation through step by step. Add prevention, appraisal, internal failure, and external failure costs to get the total cost of quality.

The inputs for this scenario

  • Prevention cost: 2,500 $ (the input this scenario stresses; the baseline uses 5,000)
  • Appraisal (inspection) cost: 8,000 $ (held at the documented default)
  • Internal failure cost: 12,000 $ (held at the documented default)
  • External failure cost: 15,000 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total cost of quality = prevention cost + appraisal cost + internal failure cost + external failure cost.
  • Total cost of quality works out to 37,500 $ at these inputs, and this is the headline figure for the scenario.
  • Element 1 works out to 2,500 $ at these inputs.
  • Element 2 works out to 8,000 $ at these inputs.
  • Element 3 + 4 works out to 27,000 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where prevention cost sits at 5,000 $ and the headline result is 40,000 $, this scenario comes in 6.25% below the baseline at 37,500 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to prevention cost, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. Many failure costs (lost customers, reputation damage, engineering rework hidden in overhead) are underreported, so the total almost always understates true CoQ.

Results at a glance

  • Total cost of quality: 37,500 $ (headline result)
  • Element 1: 2,500 $
  • Element 2: 8,000 $
  • Element 3 + 4: 27,000 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Cost of Quality calculator, set prevention cost to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.