8D Report: A Step-by-Step Guide With an Example
When a customer finds a defect, they usually ask for one thing: an 8D report. Automotive, electronics and industrial customers use it to judge whether a supplier has contained the problem, found the real root cause and stopped it from coming back. A weak 8D often costs more than the defect itself, in repeat complaints, extra audits and lost business.
This guide explains each of the eight disciplines, shows what a good answer looks like using a worked example, and lists the mistakes that get 8Ds sent back.
The example
A customer reports that 46 printed circuit board assemblies from one lot failed functional test at their line. The failure is an open joint on a connector. Delivered lot size: 2,000 boards.
D0 – Prepare and plan
Decide whether the problem needs a full 8D and take any emergency response actions. Record the complaint number, part number, lot, quantity and the date the customer reported it.
Example: Full 8D opened. Emergency response: customer informed within 24 hours, stock at the warehouse put on hold.
D1 – Form the team
Name a cross-functional team with a leader and the people who know the process: production, process engineering, quality and, where relevant, the supplier. Avoid a team of one quality engineer writing the report alone.
Example: Team leader from process engineering, with members from SMT production, quality, maintenance and the stencil supplier.
D2 – Describe the problem
Describe the problem in measurable terms. A common structure is 5W2H: what, where, when, who, why it matters, how it was detected and how many.
Example: 46 of 2,000 boards (2.3%) from lot 2610-07 show an open solder joint on pin 12 of connector J3, found at customer functional test on 20 October. Previous lots: no failures reported.
D3 – Contain the problem
Protect the customer while you investigate. Contain every suspect unit: at the customer, in transit, in your warehouse and in work in progress. Record quantities checked, quantities rejected and the method used.
Example: 1,954 boards at customer and 600 in our warehouse inspected by X-ray at J3. 12 more rejects found. Clean boards marked with a green dot. 100% J3 X-ray added at our end-of-line until D6 is verified.
D4 – Find the root cause
Find why the problem occurred and why it escaped detection. These are two separate root causes. Use tools such as a fishbone diagram and 5 Whys, and verify the cause by reproducing the defect.
Example:
- Occurrence: stencil aperture for J3 pin 12 partly blocked. Why? Stencil cleaning frequency was changed from every 5 to every 10 prints during a line change. Why? The change was not reviewed through engineering change control.
- Escape: automated optical inspection cannot see under the connector body, and X-ray sampling did not include J3.
- Verification: defect reproduced by running 10 prints without cleaning; open joints appeared from print 7.
D5 – Choose permanent corrective actions
For each root cause, choose an action and prove it works before you implement it.
Example: Restore cleaning to every 5 prints and lock the setting with a password. Add J3 to the X-ray sampling plan. Trial run of 500 boards: zero defects.
D6 – Implement and validate
Implement the actions, update the documents they affect and show data that confirms the fix in production.
Example: Machine program, work instruction and control plan updated. Three lots (6,000 boards) produced: zero J3 defects. Containment X-ray removed after the third lot.
D7 – Prevent recurrence
Stop the same problem happening on other lines, products and processes. Update systems, not just this part.
Example: Cleaning frequency locked on all printers. Engineering change procedure updated so any machine parameter change requires review. Lesson shared with the other plants. PFMEA updated for fine-pitch connectors.
D8 – Close and recognise the team
Confirm with the customer that the 8D is accepted, close the report and recognise the team.
Mistakes that get 8Ds rejected
| Mistake | What to do instead |
|---|---|
| Root cause written as "operator error" | Ask why the process allowed the error. The cause is usually missing error-proofing or training. |
| Only the occurrence cause is analysed | Always give a separate escape cause: why detection failed. |
| Containment limited to your own stock | Include customer stock, goods in transit and work in progress. |
| Actions with no owner or date | Every action needs one owner, a due date and evidence of completion. |
| Closed without validation data | Show production data after the fix, not just a statement. |
| D7 repeats D5 | D7 should change systems: procedures, FMEA, other lines and products. |
Keeping 8Ds under control
A single 8D is easy to manage in a Word template. Twenty open 8Ds across several customers and plants are not. Actions get lost in e-mail, due dates pass unnoticed and customers receive different versions of the same report.
An 8D system keeps each discipline, action, owner and due date in one record, reminds owners before actions go overdue, and keeps customer-facing revisions separate from internal history. The method stays the same. The follow-through is what changes.
CAPA & 8D software: Structured 8D and corrective action tracking with owners, due dates, effectiveness checks and customer reports. See how it works →