How to write an 8D report

The eight disciplines, in order

1. D1: Form the team

   Pick a small cross-functional team with the knowledge to solve it: quality, engineering, production, and the supplier or customer when they are part of the problem. Name a leader.

2. D2: Describe the problem

   State what is wrong, on which part, where it was found, when it started and how many are affected. Use Is / Is Not to separate what is affected from what is not. A vague problem statement is where most weak 8Ds start.

3. D3: Contain it

   Protect the customer now: sort, quarantine or hold every suspect part, wherever it is. Record dates, quantities inspected and rejected at each location, and how certified stock is identified.

4. D4: Find and verify the root cause

   Find two causes: why the defect happened, and why it escaped. Use 5-Why, a fishbone or fault tree, then verify the cause by turning it on and off or with data.

5. D5: Choose permanent corrective actions

   Pick actions that remove the verified causes, for both occurrence and escape, and confirm they work before full rollout.

6. D6: Implement and validate

   Put the actions in place, remove the temporary containment, and show with production data that the problem is gone.

7. D7: Prevent recurrence

   Change the system so it cannot come back here or on similar parts: update the PFMEA, Control Plan, work instructions and procedures, and share the lesson.

8. D8: Recognize the team

   Close the 8D and recognize the people who solved it.

Some customers add a D0 step for planning and emergency response before D1. Use your customer’s format and timing if they specify one.

The mistakes that get 8Ds rejected

• A vague problem statement. "Parts out of spec" is not a D2. Name the part, the characteristic, the measured value against the tolerance, where it was found and how many.
• Containment written as the fix. Sorting and 100% inspection protect the customer, but they are not permanent corrective action.
• Only one root cause. If you explain why it happened but not why it escaped, the next defect will escape the same way.
• "Retrained the operator." Training rarely removes a cause on its own. Ask what in the process let the mistake happen.
• Closing without proof. D6 needs data from production after the change, not a date the action was completed.
• No document updates. If the PFMEA and Control Plan did not change, D7 is not done.

Typical timing

Many customers expect containment within about 24 hours, a root cause and planned actions within days, and validated actions within weeks. The free form uses 24 hours, 7 days and 90 days as targets. Your customer’s requirements come first.