You must have about 8D, and 8D problem-solving methodologies a lot in the industry. This blog helps you to understand what is 8D and how it can be used to solve not-only industry related issues, but this can also be useful to solve day-to-day issues.
What is 8D?
8D is known as the eight disciplines of the problem-solving method. 8D is an effective tool to eliminate the re-occurrence of the problem or error by systematic analysis of the root cause of the defect/error and initiating permanent corrective actions with effectiveness criteria. 8D also covers containment action to avoid the spread of the issue or reoccurrence of the issue.
In a nutshell 8D covers,
- Quick Response / Containment Action: To stop the spread of error or defect.
- Root Cause Analysis: Defect cause and escape cause
- Corrective Action: Long-term and short-term
- Verification and Validation of Corrective Action: Mandatory!
- Effectiveness Check
Who invented the 8d methodology?
8D methodology was originally initiated by Ford Motors in 1980.
The 8D problem-solving tool is also known as the 8-discipline methodology.
The following 8 disciplines are used for problem-solving hence it is known as 8 discipline steps,
D0: Planning Phase (based on problem severity & occurrence)
D1: Team formation (Task Force)
D2: Detailed problem description
D3: Containment Action
D4: Root Cause Analysis
D5: Corrective Action
D6: Verify and Validate Corrective Action
D7: Prevent Re-occurrence.
D8: Closure and Team Recognition
Let’s discuss each 8D step one by one!
D0: Planning Phase:
Not every problem requires 8D methodology. The 8D methodology is more suitable for unknown root causes and high severity, high critical, and high occurrence problems.
In the planning phase, primary information about the problem must be collected to form the right team.
D1 Team formation:
Problem-solving requires teamwork, brainstorming, and Gemba activities, hence cross functional team formation is essential. In the cross-functional team formation step, the following factors must be considered,
- Process Owner
- Production/Machine Operator
- Subject Matter Expert (SME)
- Team members have product, process, and system knowledge.
- 8D Owner
- 8D Requester / Sponsor
- Supplier (if required)
- Design & Engineering Team (if required)
- Safety (if required)
- Maintenance (if required)
D2 Detailed Problem Description:
In this step elaborate the primary problem statement in quantifiable terms by using the 5W-2H methodology.
- Where problem observed/detected/reported?
- Who reported the problem?
- What problem is it?
- When a problem was reported?
- Why was this problem detected/missed at the detection stage?
- How severe and critical this problem is?
- How many products/customers suffered due to this problem?
Once you collect information by asking the above questions, frame the problem by considering the following details.
- Problem statement must be accurate and clear.
- The problem statement should not contain the causes of the problem
D3: Containment Action:
In D3 containment action CFT (Cross-functional team) shall focus on,
- How re-occurrence of the problem/error/defect can be stopped, and an interim correction action must be taken to avoid the re-occurrence of the problem?
- Communication to stakeholders/warehouse/dealers to isolate the defective products/errors at their end.
- Communication to a supplier: If an error/issue is supplier caused (suspected) in this case involves the supplier.
- Communication to Customers / Dealer: This step must be initiated if the problem is critical to safety and product re-call is required only! Management should consider this option if it’s really necessary to execute.
Following Containment Action can be considered.
- Sorting defective parts/products
- Stopping the production line for the time being until the interim solution is developed.
- Repairing defective parts
- Tracing defective parts which are upstream supply chain
- Gemba meeting
D4 Root Cause Analysis:
In this step, CFT needs to focus on detailed root cause analysis. Following root cause analysis tools can be considered,
- 5 Why-Why Analysis
- 5M-1E (Fishbone diagram)
- Affinity Diagram
- 3Legged – 5Why Analysis
In addition to that, the following method can also be considered for root cause analysis,
- Comparison of process as-is Vs. ideal process
- Gemba walk
- Determine possible escape point – Missing Prevention or missing detection
In this step, CFT should focus on finding the root cause of the problem and verify the same, whether the identified root cause is correct or not.
Verification of root cause can be executed by,
- Data collection and analysis,
- Simulate the process by observing the root cause.
In root cause analysis the cause of escape or the cause of non-detection also needs to be reviewed.
- Why detection point not established in the control plan?
- Why is mistake proofing not established?
CFT team needs to focus on why prevention actions or prevention checkpoints were missed or not prevented the error or defect.
- Why did D-FMEA / P-FMEA fail to establish an effective prevention point?
- Why control plan failed to establish a prevention check?
D5: Corrective Action
The CFT team must focus on an effective solution to eliminating defects/errors by analyzing the root cause. The solution differs from industry to industry, but following common corrective actions can be considered to resolve issues.
|Implementation of mistake proofing||Operator training|
|Replacing manual processes with automation||Risk assessment|
|Update P-FMEA & Control Plan||Design Changes|
|Lean Manufacturing – Eliminate waste, over-production.||6 Sigma – DMAIC / DFSS|
In the corrective action phase, CFT must focus on
- How to implement preventive action
- How to implement detection point (Escape point)
D6 Verification and Validation of Corrective Action:
Verification and validation of corrective action are necessary for the successful elimination of root causes and for avoiding the reoccurrence of errors or defects.
In the verification phase: Verify all necessary details of corrective actions such as updated work instruction, calibrated tools/instruments, updated PFMEA, Updated control plan.
In the Validation phase: Once verification of corrective actions is completed, focus on the implementation of corrective action and measure the process behavior or process outcome.
If the process outcome is as expected and meets the target, document the validation details and implement the process.
For Validation, the following tools can be considered.
- Process capability (Cp, Cpk)
- Functional Testing of the product
D7 Effectiveness Check:
In this effectiveness check step, the focus should be on
- How re-occurrence of the problem can be avoided?
- Horizontal deployment of corrective actions
How to avoid the re-occurrence of the problem?
Step 1: Implement verified and validated corrective action and keep observing the output.
Step 2: If desired process outcome is achieved without any abnormal/side effects. Update work instructions and deploy the corrective action permanently.
Step 3: Document effectiveness checks with proper records and sign-off by CFT.
Horizontal Deployment of Corrective Actions:
Implementation of corrective action to avoid a problem or error is essential however it’s CFT’s responsibility to look for a similar problem or potential risk in similar product lines and processes.
- Inform your regional or international subsidiary function/business unit of similar issues and corrective actions
- Inform suppliers of similar kinds of issues
- Update internal company standards and one QMS for the horizontal deployment of processes and standard requirements.
- Update the mistake-proofing log, so it can be referred to by other business units while designing a new process.
8D: Closure and Team Recognition:
Once you are done with the effectiveness check and horizontal deployment step, the next step is to close the 8D with team recognition. It’s a very important step to showcase the 8D outcome to the leadership and recognition of each CFT member. This will boost a good quality culture within the organization.