Poka-yoke payback calculator

Is an error-proofing fixture worth it? Enter how often the mistake happens, what it costs and what the fixture would cost, and see the payback period and first-year return.

Pays for itself in–
  • Savings per year–
  • First-year return (after fixture cost)–
  • First-year ROI–

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How the calculation works

Weekly savings = mistakes per week × cost per mistake × share prevented, plus inspection hours no longer needed × labour rate. Payback is the fixture cost divided by weekly savings. First-year ROI compares a year of savings with the fixture cost.

It's deliberately conservative: it ignores customer goodwill, less firefighting and the training time saved when the process can only be done one way.

Getting the inputs right

  • How often: use your defect log or NCRs for the last 3 months, divided by 13.
  • Cost each time: use the escape cost if the mistake reaches customers; it's usually far higher than rework.
  • Share prevented: a physical fixture that makes the wrong way impossible is close to 100%; a warning light is lower.
  • Fixture cost: simple 3D-printed nests and pins cost far less than sensor or vision systems. See how poka-yoke fixtures are designed and digital poka-yoke options.

Not sure what a defect costs you overall? Start with the cost of poor quality calculator.

Common questions

What is a good payback period for a poka-yoke?

Many simple error-proofing devices pay back in weeks. Under three months is usually an easy decision; under a year is still worthwhile for most manufacturers.

How much does a poka-yoke fixture cost?

It ranges widely: a 3D-printed locating nest or pin can be inexpensive, while sensor, interlock or vision systems cost more. The mechanism, materials and integration drive the price.

Should I count inspection time saved?

Only if you would actually reduce inspection once the error is prevented. If you'd keep inspecting, set it to 0.