Cost of Poor Quality (COPQ) Calculator
Calculate the total Cost of Poor Quality (COPQ) by summing internal failure costs, external failure costs, appraisal costs, and prevention costs across your organization.
Internal Failure Costs
Costs from defects found before the product/service reaches the customer.
External Failure Costs
Costs from defects found after the product/service reaches the customer.
Appraisal Costs
Costs of measuring, evaluating, and auditing quality.
Prevention Costs
Costs of activities to prevent defects from occurring.
Revenue Reference (Optional)
Formula
COPQ = Internal Failure Costs + External Failure Costs + Appraisal Costs + Prevention Costs
Based on the PAF (Prevention–Appraisal–Failure) Model (Feigenbaum, 1956; ASQ):
- Internal Failure Costs = Scrap + Rework + Re-inspection + Downtime + Yield Loss
- External Failure Costs = Warranty + Complaints + Liability + Lost Sales + Field Service
- Appraisal Costs = Inspection + Audits + Equipment Calibration + Supplier Evaluation
- Prevention Costs = Training + Process Improvement + Quality Planning + Preventive Maintenance
- COPQ % of Revenue = (Total COPQ ÷ Total Revenue) × 100
- Failure Cost = Internal Failure + External Failure (the "hidden factory" cost)
Assumptions & References
- Uses the ASQ PAF (Prevention–Appraisal–Failure) Cost of Quality model. Some frameworks define COPQ as only failure costs (internal + external), excluding prevention and appraisal; this calculator follows the broader ASQ definition.
- Lost sales are an estimated/opportunity cost and may be difficult to quantify precisely; include only if a reasonable estimate is available.
- Industry benchmarks: COPQ typically ranges from 5–30% of revenue for most organizations (ASQ). World-class companies achieve below 5%.
- Prevention costs are considered "good" investments — increasing prevention typically reduces failure costs by a greater amount (the 1:10 quality cost ratio rule).
- All inputs default to $0 if left blank. Negative values are not accepted.
- References: Feigenbaum, A.V. (1956). Total Quality Control; ASQ. The Economics of Quality; Juran, J.M. & Gryna, F.M. (1988). Juran's Quality Control Handbook.