An 8D is a supplier's structured problem report built on eight disciplines, one non-conformance per report, running from stopping the bad parts to preventing a repeat. With an overseas supplier the report also drives logistics and customs: which parts you quarantine, which you ship back, and which costs you can still recover.
What is an 8D report and what has to be in it?
An 8D answers a single non-conformance with a team, a measurable problem description, containment, a verified root cause, a verified fix, and a change to the process documents. It is not an inspection report and not a list of everything wrong with the delivery. When a supplier sends a spreadsheet of defects with no team, no containment record and no root cause, the file name says 8D and the content does not.
The format is not optional inside the automotive chain. VDA describes 8D as a mandatory approach for German OEMs, aligned with AIAG's CQI-20 problem solving guide. Buyers outside automotive borrow the structure because it forces two questions that a complaint email skips: why the part was made wrong, and why inspection did not catch it.
The useful part of the report is D3 and D4. A polished team chart with an empty root cause is worse than no report, because it closes the issue in your quality system while the process stays unchanged.
Which eight disciplines does an 8D follow?
Table 1. The eight disciplines, the question each answers, and the evidence to demand
| Step | Question it answers | Evidence to demand |
|---|---|---|
| D1 Team | Who owns the problem, with what authority? | Named roles, a plant manager or process owner in the group, date of the first meeting |
| D2 Problem | What is wrong, how many, where, since when? | Part number and drawing revision, lot or serial numbers, quantity inspected and quantity defective, measured values against the drawing |
| D3 Containment | How is the escape stopped now? | 100% sort record with quantities in and out, defectives found, clean point by date and lot, certified stock labelled and separated |
| D4 Root cause | Why did it occur, and why did it escape? | Two causes, each with the test or data that confirmed it; reduction of the 5 Why or Is/Is-Not to a controllable process variable |
| D5 Corrective action | Which fix removes the cause? | Options considered, the one chosen and why, trial data before and after |
| D6 Implementation | Is the fix in the process, and does it hold? | Revised work instruction, PFMEA and control plan with revision numbers and effective dates; effectiveness data over a stated quantity and period |
| D7 Prevention | Where else can this fail? | Read-across to other part numbers, machines, shifts and customers; updated documents; entry in the lessons-learned file |
| D8 Closure | Who signs it off, and what is acknowledged? | Buyer acceptance with a date, team acknowledgement, link to the credit note if one was raised |
Source: VDA QMC, 8D Problem Solving training flyer, version July 2024, list of disciplines D1 to D8; the flyer states the method is aligned with the AIAG CQI-20 Problem Solving Practitioner Guide.
Read the table as a checklist for the report, not a script for the supplier. A short report with data beats a forty-page one that repeats D2.
What belongs in D3 containment with a supplier far away?
Containment protects your line and your customer. It does not fix anything, and it ends when the permanent action is validated. The delivery pipeline keeps moving while the analysis is starting, so the sort has to cover material already in transit.
Four items make the difference:
- Scope of the sort. The suspect population is more than the shipped lot. Ask for everything produced between the last known-good check and the detection, including stock on the road.
- Sort result as a number. Units sorted, defectives found, and the defect rate in the suspect population. That rate tells you whether your own stock is contaminated.
- A clean point. A dated, identified boundary, usually a lot number or serial range, after which material is verified. Without it the sort never ends.
- Certified stock. Containers labelled, signed and physically separated from unverified material, with the certificate traceable to the sort record.
Then agree who pays. Sorting at your dock costs labour and floor space; charge it back against the credit note.
How do you judge whether the root cause analysis is real?
Two causes, not one. The occurrence cause explains why the part was made out of specification. The escape cause explains why the supplier's inspection released it. A report that answers only the first will ship the same defect again with a different measurement story.
Three tests separate analysis from narrative:
- Can the cause be switched on and off? A real cause can be reproduced by restoring the condition, and disappears when the condition is removed. If nothing was reproduced, the cause is a hypothesis.
- Does the corrective action touch a process variable? "Operator error, retraining given" is not a root cause, because the retrained operator will be replaced. The controllable version is usually a fixture, a tool life limit, a parameter window or a poka-yoke.
- Was the gauge itself investigated? For the escape cause, ask for the gauge, the sampling plan and the inspection stage. A worn gauge or a feature missing from the plan will pass a bad part indefinitely; a gauge R&R on the failing characteristic is the evidence that this was checked.
A five-why chain should end at something the supplier can change and measure, not at "awareness".
How do you close an 8D so the problem does not return?
Closure is a validation, not a signature. D6 needs a quantity and a period that the original failure rate would have exposed. "Three lots without recurrence" means little if the escape rate was one part in ten thousand; ask what sample would have shown the defect if it were still there, and why that sample is large enough.
D7 is where most overseas 8Ds are thin. The same feature usually exists on other part numbers, runs on the same machine, or comes from the same raw material batch. Ask for the read-across list in writing and check that the PFMEA and control plan revisions match it.
Close on four conditions: effectiveness data covers the agreed quantity, the documents carry revision numbers and effective dates, read-across is complete, and the buyer signs with a date. Keep the 8D number in the supplier scorecard. If the same failure mode returns, reopen the 8D instead of accepting a new one; a reopened report shows D7 failed.
Should you return the parts, scrap them or take a credit?
Decide before the containment sort ends: the choice determines what you keep as evidence.
Table 2. Disposition routes for non-conforming parts
| Route | When it fits | Cost and risk |
|---|---|---|
| Return to supplier | High value, repairable, or the supplier needs the parts to reproduce the failure | Freight both ways, weeks of transit, customs paperwork; duty recovery has a deadline |
| Rework on site | Simple, well-understood defect and the supplier approves the procedure in writing | Your labour and floor space; the part leaves the drawing unless a concession is agreed |
| Scrap locally | Low value, high freight, or the defect is proven by data | Loss of physical evidence; destruction under customs supervision if duty is to be repaid |
| Credit note, no return | Cheap parts, defect proven by measurement and photographs | Nothing physical to inspect; insist on a use-as-is concession if the parts are to be used |
Keep two or three defectives per failure mode, plus photographs with a scale, the measurement data and the packaging label. A supplier cannot reproduce a failure from a description, and a returned lot without samples gives them nothing to work with.
What does EU customs require when rejects go back?
If the goods were imported into the EU and duty was paid, the Union Customs Code gives a route to recover it. Article 118 applies where the importer rejected goods that were defective or did not comply with the contract at the time of release. The goods must not have been used beyond what was needed to establish the defect, and must leave the EU customs territory.
Article 118(4) allows an alternative to export. On application, customs can authorise inward processing including destruction, or external transit, customs warehousing or a free zone. Scrapping in your yard without customs involvement does not satisfy the article.
Three limits decide whether a claim is worth the paperwork:
- One year. The application is due within one year of notification of the customs debt (Article 121(1)(b)), not one year from the delivery date.
- EUR 10. Repayment is granted where the amount reaches EUR 10 or more (Article 116(2)).
- Exclusions. No repayment if the defect was already reflected in the contract price, if the goods were sold after the defect was established, or if a pre-release testing procedure could normally have detected it (Article 118(3)).
For a Turkish supplier the duty line is often zero. Industrial goods move between the EU and Türkiye free of customs duty under Decision No 1/95, in force since 1 January 1996, when an A.TR certificate proves their status. Coal and steel products stay outside that arrangement, so a claim can still matter for some steel parts. See the customs union guide for the certificate rules. Article 118 covers import duty; import VAT is a separate claim under national VAT rules.
Keep the import declaration and its MRN, the commercial invoice and packing list, the rejection record with measurement data, and a return invoice that references the original invoice and the 8D number. Status as of 2026-11-03; customs authorities apply the code through national procedures, so confirm the forms and evidence list locally.
Our network in Bursa works to ISO 2768-m as standard and tighter where the drawing specifies it, and we would rather receive the measurement data and two samples than a returned pallet, because the data is what closes D4. The quality documents guide covers the certificates that travel with a delivery, and PPAP for tier 2 suppliers covers the approval package that should have prevented the escape in the first place.
Frequently asked questions
- What is an 8D report?
- A supplier's structured problem report covering eight disciplines: team, problem description, containment, root cause, choice of corrective action, implementation and validation, prevention, and closure. One report covers one non-conformance.
- Is an 8D the same as a corrective action report?
- Not quite. A corrective action report is the buyer's request, often one page. The 8D is the supplier's answer, and it carries containment evidence, two root causes and proof that the fix worked over a defined quantity.
- How long should a supplier take to close an 8D?
- The method sets no fixed period. Agree two clocks in the purchase order: a containment deadline in hours and a closure deadline in weeks, counted from the complaint date rather than from the supplier's first reply.
- Do I have to send defective parts back to get a credit?
- No. Many suppliers credit a defect proved by measurement data and photographs, especially on low-value parts where freight exceeds the value. Keep two or three samples per defect mode before you scrap anything.
- Can I reclaim import duty on rejected parts?
- Yes, under Article 118 of the Union Customs Code, if the goods were defective or non-conforming when released, were not used beyond what was needed to establish the defect, and leave the EU customs territory. The application is due within one year of notification of the customs debt.
- Does the EU-Türkiye customs union change the return?
- It usually removes the duty from the calculation. Industrial goods from Türkiye enter at 0% duty under Decision 1/95 when an A.TR certificate proves their status, so on a return to a Turkish supplier the money at stake is freight and import VAT rather than customs duty.
Sources
- VDA QMC, 8D Problem Solving training flyer, version July 2024, list of disciplines D1 to D8 (VDA China)
- AIAG, CQI-20-2 Effective Problem Solving Guide (publication page)
- AIAG, U8DA Taking Effective Corrective Action: Using the 8-D Approach (course page)
- Regulation (EU) No 952/2013 (Union Customs Code), Title III Chapter 3 Section 3, Articles 116 to 121: repayment and remission
- Regulation (EU) No 952/2013, Chapter 3 full text, Article 121(1)(b): one-year period for defective goods
- European Commission, DG TAXUD: customs unions and preferential arrangements, A.TR certificates, coal and steel outside the customs union
- European Commission, DG Trade: EU trade relations with Türkiye, Customs Union Decision No 1/95 in force since 1 January 1996
Questions on a drawing? sales@ertas.engineering