L’8D analysis (or Eight Problem-Solving Disciplines) is a structured, highly rigorous problem-solving methodology, standardized and widely adopted in industry, particularly in the automotive sector. It is a Root Cause Analysis (RCA) to solve a recurring or critical problem quickly, efficiently and permanently.
In-depth definition : The 8D approach is a process reagent (unlike the’FMECA which is preventive) that is triggered when a major customer defect, a serious non-conformity or a failure having a significant impact on the Industrial Performance is identified (for example, a critical drop in the TRS or a high number of rejects). It focuses on collaboration and the standardization actions. It doesn't just find a quick fix, but ensures that the root cause (Root Cause) is eliminated and measures are taken to ensure that the problem never occurs again.
The Eight Steps (Disciplines) of 8D Analysis
8D analysis is a logical process, often documented in a standardized report, which fits perfectly into the PDCA (Plan-Do-Check-Act) :
D1. Team building (Plan)
- Objective: Set up a multidisciplinary team.
- Action: Involve the people who know the product or process best (Quality, Production...), Industrial Engineering, Maintenance, etc.).
D2. Describe the problem (Plan)
- Objective: Define the problem clearly and factually.
- Action: Use of 5W2H (What, Where, When, Who, Why, How, How much) and production data (Big Data from the MY) to quantify the deviation and identify the non-conformity to the Technical specifications.
D3. Implement Containment Actions (Emergency Action)
- Objective: Protect the customer and stop the bleeding.
- Action: Isolate and sort potentially defective products (in-process, warehouse and customer inventories) to guarantee Quality for future deliveries.
D4. Root Cause Analysis (RCA)
- Objective: Identify the root cause of the problem.
- Action: Use of analysis tools (Ishikawa, 5 Whys) to move from the cause of the symptom to the root cause of the system malfunction (e.g.: faulty Standardization or Poka-Yoke missing).
D5. Determine and Check Permanent Corrective Action (Plan/Do/Check)
- Objective: Find the solution that will eliminate the root cause.
- Action: Define and test the solution. Testing is crucial and must demonstrate that the problem has been solved definitively (phase Check from PDCA). Analysis Pareto can help target the most effective solution.
D6. Implement Permanent Corrective Action (Act)
- Objective: Deploy the tested and validated solution at scale.
- Action: Implementation of the solution, updating of the Bill of materials (BOM), the Manufacturing range and Work Instructions in the Manufacturing file (phase Act from PDCA).
D7. Implement preventive actions (Prevention)
- Objective: Apply the solution to other similar products or processes to avoid recurrence elsewhere (capitalization).
- Action: Update FMECA and share the lesson learned (lesson learned from the KAIZEN).
D8. Congratulate the Team (Closing)
- Objective: Recognize the collective effort and officially close the cycle.
8D and Operational Excellence
L’8D analysis is a pillar of the’Continuous Improvement. It structures the resolution process to transform each crisis from one of Quality into an opportunity to learn and strengthen processes. It is an indispensable tool for a lasting commitment to eliminating waste (Muda) caused by faults and failures, guaranteeing greater reliability of the Series Production.