How to Apply Eight Disciplines of Problem Solving (8D)
The 8D process alternates inductive and deductive problem solving tools to relentlessly move forward toward a solution. The Quality-One approach uses a core team of three individuals for inductive activities with data driven tools and then a larger Subject Matter Expert (SME) group for the deductive activities through brainstorming, data-gathering and experimentation.
D0: Prepare and Plan for the 8D
Proper planning will always translate to a better start. Thus, before 8D analysis begins, it is always a good idea to ask an expert first for their impressions. After receiving feedback, the following criterion should be applied prior to forming a team:
Collect information on the symptoms
Use a Symptoms Checklist to ask the correct questions
Identify the need for an Emergency Response Action (ERA), which protects the customer from further exposure to the undesired symptoms
D1: Form a Team
A Cross Functional Team (CFT) is made up of members from many disciplines. Quality-One takes this principle one step further by having two levels of CFT:
- A Core Team uses data-driven approaches (Inductive or Convergent Techniques)
- The Core Team Structure should involve three people on the respective subjects: product, process and data
- SME Team comprised of members who brainstorm, study and observe (Deductive or Divergent Techniques)
- Additional Subject Matter Experts are brought in at various times to assist with brainstorming, data collection and analysis
Teams require proper preparation. Setting the ground rules is paramount. Implementation of disciplines like checklists, forms and techniques will ensure steady progress. 8D must always have two key members: a Leader and a Champion / Sponsor:
- The Leader is the person who knows the 8D process and can lead the team through it (although not always the most knowledgeable about the problem being studied)
- The Champion or Sponsor is the one person who can affect change by agreeing with the findings and can provide final approval on such changes
D2: Describe the Problem
The 8D method’s initial focus is to properly describe the problem utilizing the known data and placing it into specific categories for future comparisons. The “Is” data supports the facts whereas the “Is Not” data does not. As the “Is Not” data is collected, many possible reasons for failure are able to be eliminated. This approach utilizes the following tools:
- 5 Why or Repeated Why (Inductive tool)
- Problem Statement
- Affinity Diagram (Deductive tool)
- Fishbone/Ishikawa Diagram (Deductive tool)
- Is / Is Not (Inductive tool)
- Problem Description
D3: Interim Containment Action
In the interim, before the permanent corrective action has been determined, an action to protect the customer can be taken. The Interim Containment Action (ICA) is temporary and is typically removed after the Permanent Correct Action (PCA) is taken.
- Verification of effectiveness of the ICA is always recommended to prevent any additional customer dissatisfaction calls
D4:Root Cause Analysis (RCA) and Escape Point
The root cause must be identified to take permanent action to eliminate it. The root cause definition requires that it can be turned on or off, at will. Activities in D4 include:
- Comparative Analysis listing differences and changes between “Is” and “Is Not”
- Development of Root Cause Theories based on remaining items
- Verification of the Root Cause through data collection
- Review Process Flow Diagram for location of the root cause
- Determine Escape Point, which is the closest point in the process where the root cause could have been found but was not
D5: Permanent Corrective Action (PCA)
The PCA is directed toward the root cause and removes / changes the conditions of the product or process that was responsible for the problem. Activities in D5 include:
- Establish the Acceptance Criteria which include Mandatory Requirements and Wants
- Perform a Risk Assessment /Failure Mode and Effects Analysis (FMEA) on the PCA choices
- Based on risk assessment, make a balanced choice for PCA
- Select control-point improvement for the Escape Point
- Verification of Effectiveness for both the PCA and the Escape Point are required
D6: Implement and Validate the Permanent Corrective Action
To successfully implement a permanent change, proper planning is essential. A project plan should encompass: communication, steps to complete, measurement of success and lessons learned. Activities in D6 include:
- Develop Project Plan for Implementation
- Communicate the plan to all stakeholders
- Validation of improvements using measurement
D7: Prevent Recurrence
D7 affords the opportunity to preserve and share the knowledge, preventing problems on similar products, processes, locations or families. Updating documents and procedures / work instructions are expected at this step to improve future use. Activities in D7 include:
- Review Similar Products and Processes for problem prevention
- Develop / Update Procedures and Work Instructions for Systems Prevention
- Capture Standard Work / Practice and reuse
- Assure FMEA updates have been completed
- Assure Control Plans have been updated
D8: Closure and Team Celebration
Teams require feedback to allow for satisfactory closure. Recognizing both team and individual efforts and allowing the team to see the previous and new state solidifies the value of the 8D process. Activities in D8 include:
- Archive the 8D Documents for future reference
- Document Lessons Learned on how to make problem solving better
- Before and After Comparison of issue
- Celebrate Successful Completion
