8D Problem Solving Course

Nine short lessons, one per discipline, all following the same real-life case from customer complaint to closure. About one hour. Your progress is saved in this browser.

Case: a car maker rejects 52 housings because the bore diameter Ø 32 H7 is oversized by up to 0.013 mm. The housings come from CNC line 3 of your plant.

Lesson 1 of 9

Prepare and decide if an 8D is needed

Decide whether the problem needs a full 8D and protect the customer from the first hour.

Use an 8D for customer complaints, repeated or safety-related problems and anything with unknown cause.
Record the complaint data: part number, quantity, date codes, photos, customer reference.
Start emergency response actions (ERA) right away if the customer line is at risk.

Case study

The complaint arrives on Monday 08:00. Severity is high (assembly stops at the customer), the cause is unknown: a full 8D is opened, number 8D-2026-014.

Common mistakes

Waiting for the formal 8D before reacting.
Opening an 8D for a known, already fixed issue (use a simpler corrective action).

Check your understanding

When is a full 8D appropriate?

Case: a car maker rejects 52 housings because the bore diameter Ø 32 H7 is oversized by up to 0.013 mm. The housings come from CNC line 3 of your plant.

D0 Prepare and decide if an 8D is needed: Decide whether the problem needs a full 8D and protect the customer from the first hour.

D1 Build the team: Put together a small, cross-functional team with the knowledge and authority to solve the problem.

D2 Describe the problem: Describe the problem so precisely that the cause search becomes narrow.

D3 Contain the problem: Protect the customer immediately until the permanent fix works.

D4 Find and verify the root cause: Find why the defect occurred and why it was not detected, and prove both.

D5 Choose permanent corrective actions: Select actions that remove the root causes and prove, before full rollout, that they will work.

D6 Implement and prove effectiveness: Put the actions in place and show with data that the problem is gone.

D7 Prevent recurrence: Make sure the same cause cannot create the same problem anywhere else.

D8 Close and recognise the team: Formally close the 8D with the customer and recognise the team.