8D has become a standard in the auto, assembly, and other industries that require a thorough structured problem-solving process using a team approach. The 8D process takes several problem-solving tools and combines them into one uniform model. It is for this reason that many companies do not use full 8D problem solving techniques. The model is so comprehensive that many lean professionals steer clear of this process due to the cumbersome requirements.
8D problem solving, also known as Global 8D Problem Solving, has its roots in Military Standard 1520, developed during World War II to deal with quality issues. During the 1960s, Ford Motor Company built on MIL-STD-1520 to develop 8D problem solving into a powerful business tool. While Ford continued to improve 8D problem solving throughout the ‘70s, ‘80s and ‘90s, the MIL-STD-1520 was replaced in 1992 by Q9001, which is based on ISO 9000.
The Eight Disciplines of 8D Problem Solving
The name “8D problem solving” comes from the eight disciplines, or steps in the process. In the 1980s, Ford added a ninth discipline to start the process, “planning.” However, the name “8D Problem Solving” was retained. The disciplines are:
- D0 – Plan
- D1 – Put Together A Team
- D2 – Define the Problem
- D3 – Implement a Temporary Fix
- D4 – Identify Root Causes and Choose a Solution
- D5 – Confirm The Solution Resolves The Problem
- D6 – Fully Implement the Solution
- D7 – Prevent Recurrence
- D8 – Recognize the Team
8D problem solving is based on identifying, correcting, and eliminating recurring problems. The goal is to focus on root causes, and implement a verified solution that permanently eliminates the root cause of the problem. 8D problem solving is a comprehensive approach; do not skip or “shortcut” any of the steps. This will undercut the effectiveness of 8D, and may result in the root cause not being eliminated.
D0 – Plan
A problem has been identified; what are you going to do about it? In this first step, a plan is established that defines the type of people needed on the team, the required resources, the schedule, and how the team will function.
D1 – Put Together a Team
The team should be tailored to the process or product being examined, and should include knowledgeable people who have been involved in the design, operation, and maintenance of the process or product. In some cases including people from departments such as accounting or purchasing may be appropriate. At times a customer representative may even be included on the team.
At the first team meeting, create a Team Purpose Statement describing why the team has been brought together and the objectives the team needs to accomplish.
D2 – Define the Problem
The second step involves describing the problem in detail using quantifiable terms. This may require collecting data and interviewing those who are directly involved with the process or product. Get the answers to the Five “W” questions: Who, What, Where, When, and Why.
A risk analysis should also be conducted to determine if there are hazards to people or the environment. The team should have the authority to stop the sale of a product, or stop a process, if a serious health or injury hazard is uncovered.
D3 – Implement a Temporary Fix
If the problem is impacting customers, product quality, or productivity, identify and implement a temporary fix. Do not be haphazard in doing a temporary fix. Be sure that it is safe, effective, easy to implement, and worth the effort.
D4 – Identify Root Causes
Use techniques such as brainstorming, Fault Tree Analysis, and fishbone diagrams to identify the root cause. Also study the situation and any previous responses to the problem, or its related symptoms, to determine why the problem had not been fixed previously. Once the root cause has been identified, develop a solution to eliminate it.
D5 – Confirm the Solution Resolves The Problem
Test the product or process to verify the solution eliminates the root cause of the problem. The tests should be quantitative, and usually involve collecting the same type of data that was used to characterize the problem in D2. Also ensure that the changes implemented as a part of the solution will not negatively impact other parts of the process or product.
If 8D problem solving is being used to address a problem in manufacturing cells, or where there are multiple machines, it can be tested in just one of these. This one location can be evaluated to determine whether the root cause was eliminated before implementing the solution in all cells or machines.
If the proposed solution is not 100% effective, reevaluate the solution and make adjustments. It may be necessary to go back to D2 and conduct a more in-depth study to identify root causes.
D6 – Fully Implement the Solution
Identify the best solution and implement it. If it was tested in a single manufacturing cell or machine, implement it in all cells or machines. Any temporary fixes should be removed and the best solution made permanent.
D7 – Prevent Recurrence
Update operating, maintenance, and inspection standards to reflect the changes that have been made. Be sure that informal practices are incorporated into the standards, if they result in a positive outcome. Also be sure to address any changes in training that may be needed, as well as changes to safety rules and practices. Finally, ensure that management practices are in alignment with the changes that have been made. The objective is to ensure that all necessary changes, at all levels in the organization, are implemented so that the problem will be permanently eliminated.
D8 – Recognize the Team
Be sure to recognize the work of the team by saying “thank you” in some way. Also recognize the efforts of those outside the team who contributed to the team’s success. These may be maintenance staff who modified equipment, engineers who redesigned part of a process, or a customer who provided valuable feedback. The “thank you” may be simple, but it should be public so that others in the organization know about what has been accomplished.