How much do defects and rework cost us?
№ 199 · Cost of poor quality
Definition
MetricCost of poor quality, internal failure plus external failure, as a share of revenue
Unit% of revenue
Line of (rework plus scrap plus warranty) divided by revenue over time. Build by aggregating defect-related costs. Above 3% means quality program needed; below 1% is best-in-class. Example: 3.2% Q1, 2.1% Q4 (quality program working after process change).
Benchmarks
| Bottom 30% | Median | Top 30% |
|---|---|---|
| 20% or more, reaching 40% at the extreme | 10% to 15% of revenue | under 5% of revenue |
Manufacturing and service organisations, Prevention-Appraisal-Failure framing from Juran and the American Society for Quality. Bands cover total quality-related cost; failure-only definitions land roughly half as high. Estimates are long-standing rules of thumb rather than an annually sampled panel. · This is the weakest evidence base in the section and the bands should be treated as orientation, not measurement. The widely quoted ASQ figures of 10 to 20% of sales rising to 40% for poor performers are decades-old estimates that continue to be republished rather than re-sampled, so a 2026 reader is looking at 1980s and 1990s framing. They also disagree sharply with a Gartner-attributed average cost of quality near 5% of revenue, and the disagreement is definitional: whether prevention and appraisal are in the numerator, and whether hidden costs such as expedite freight, re-inspection and engineering firefighting are counted. Fix the definition first and state it on the chart. Practitioner analysis consistently finds hidden cost running 4 to 5 times the visible charge, which is why measured COPQ almost always rises in the first year of proper tracking.
Category split omitted: No two independent Tier 1-2 sources publish COPQ by sector on a comparable definition; the available splits come from single-publisher syntheses of the same underlying ASQ estimates.
When it looks bad
The visible bars for scrap, rework and warranty stay small and flat while the total keeps climbing, because the growth sits in unmeasured buckets such as expedite freight, re-inspection labour and engineering time spent firefighting.
Reported COPQ shows 3.1% of revenue while 18% of orders come back and 6% need a second shipment. Loading reverse logistics, re-inspection and the customer credit puts true failure cost near 11%.
What to do about it
- Build the baseline as failure cost only, internal plus external, divided by revenue, and publish it monthly beside prevention spend. The mechanism is shifting spend from failure to prevention, and the two numbers have to sit on the same chart for the trade to be visible (ASQ Prevention-Appraisal-Failure framing).
- Cost the top three defect codes end to end, including expedite freight, re-inspection labour and the customer credit, not just the scrapped part. Practitioner analysis puts hidden cost at 4 to 5 times the visible charge, so a partial costing will rank the wrong defects first (Jama Software, 2026).
- Target a 20 to 30% relative COPQ reduction over 24 months instead of a percentage-point target, because the baseline usually rises in year one as measurement improves. Digital audit rollouts in the ASQ and BCG Quality 4.0 study reached 50% quality cost reduction and 73% lower internal parts per million at the top end (Certainty Software, citing ASQ and BCG).
- Add a structured returns-reason taxonomy at the point of return and route the leading code back to buying or product weekly. Returns are the single largest external failure bucket in retail at 15.8% of sales in 2025, and roughly 9% of them are fraudulent, so the same data feeds both quality and loss prevention (NRF and Happy Returns, 2025).
Sources
- American Society for Quality, reported by Mooncamp ASQ estimates quality-related costs at 10 to 20% of revenue for typical companies, rising to 40% for poor performers. World-class organisations hold cost of quality below 5%. mooncamp.com ↗
- Quality Digest COPQ typically amounts to 5 to 30% of gross sales for manufacturing and service companies. In the cited case, repair, rework, scrap, service calls, warranty claims and obsolete write-offs aggregated to 20% of annual sales. qualitydigest.com ↗
- Fabrico COPQ consumes 15 to 20% of total sales revenue for many manufacturers and most of it is hidden. Worked example: 2% scrap at full unit cost plus 3% rework at half unit cost equals 3.5% of production cost from internal failure alone, before any external failure. fabrico.io ↗
- Manufacturing Lead Generation, citing ASQ, Learn Lean Sigma and EASE COPQ for typical manufacturers ranges 10 to 30% of annual revenue while world-class manufacturers hold it below 5%. Scrap and rework alone cost the average manufacturer up to 2.2% of annual revenue (EASE, 2026). manufacturingleadgeneration.com ↗
- Gartner, reported by Olanab Consults Gartner found an average cost of quality around 5% of revenue with a roughly equal split between good quality (prevention and appraisal) and poor quality (failures). This sits far below the ASQ estimates and the difference is definitional. olanabconsults.com ↗
- ASQ and BCG Quality 4.0 study, reported by Certainty Software IISE benchmarks put quality-related cost at about 15% of the sales dollar. The ASQ and BCG Quality 4.0 study found digital audit programmes achieving 50% reductions in quality costs and 73% lower internal parts per million at the top end of rollouts. certaintysoftware.com ↗
- Jama Software Worked example puts failure costs at 19% of quarterly sales for a device team. Hidden costs including engineering firefighting, delayed launches and lost trust typically run 4 to 5 times the visible charge, so a 50,000 USD warranty charge realistically carries 250,000 USD of total impact. jamasoftware.com ↗
- National Retail Federation and Happy Returns Retailers estimate 15.8% of 2025 annual sales will be returned, totalling 849.9 billion USD, down from 16.9% and 890 billion USD in 2024. Around 9% of all returns are fraudulent, which is external failure cost that sits outside most quality systems. nrf.com ↗