Calculator Library / COPQ
Turn a defect rate and failure costs into the number leadership listens to: total Cost of Poor Quality, its share of revenue, where it lands, and the ROI of fixing it. A defect rate from the Capability, OEE, or Sigma tools loads here automatically.
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Where the cost lands
Inputs
Volume & rate
Failure costs
Improvement project
Instructions
COPQ models are only as strong as the cost assumptions behind them. Use this as a directional management tool and refine the cost inputs as your accounting and quality data improve.
Lost opportunity is often the hardest value to estimate. Even a rough, conservative figure is useful because it keeps poor quality from looking cheaper than it really is.
COPQ turns quality problems into financial language. This estimator helps teams convert defect rates, rework, scrap, inspection burden, warranty exposure, and lost opportunity into a total cost picture that leadership can compare against improvement investment.
It is especially useful when quality engineers need to move a conversation beyond percent defective and into margin, revenue impact, and avoided loss.
| Cost Category | How It Is Used | Typical Examples |
|---|---|---|
| Internal failure | Costs before shipment | Scrap, rework, sorting, downtime, extra inspection. |
| External failure | Costs after escape | Returns, warranty, complaint handling, field service. |
| Appraisal | Costs to detect issues | Inspection labor, test effort, audits, verification checks. |
| Opportunity loss | Commercial impact | Lost sales, margin erosion, delayed launch, damaged trust. |
If a process runs 100,000 units per year at a 2% defect rate, with average scrap/rework cost of $12 per bad unit, $18,000 in additional inspection labor, and $25,000 in annual warranty returns, the direct COPQ already exceeds $67,000 before any lost-sales impact is considered.
Once the defect rate improves, the calculator helps estimate the financial return on a project so the business case is tied to actual process performance, not vague improvement language.
COPQ usually includes internal failure, external failure, and often appraisal burden that exists because the process is not trusted to run cleanly.
It can be, especially when inspection is being used to compensate for unstable process design rather than to confirm a stable process.
Because quality problems damage delivery, trust, market share, and margin. The full business impact is often much larger than scrap alone.
Use it to rank where quality loss is financially concentrated, then compare likely project savings against implementation cost and effort.
Underestimating the hidden costs such as sorting, schedule disruption, expediting, and customer confidence damage.
Use the Project ROI shell when COPQ reduction needs to become a larger investment case with payback, NPV, scenarios, and stakeholder reporting.
Use PFMEA to attack the high-cost failure modes before they keep showing up in the COPQ estimate.
Use it to connect the cost view back to prevention, system design, and leadership responsibility.