A systematic approach to nonconformity management and continuous improvements are the key elements of every management system. 8D methodology uses a structured eight step approach to problem solving. The objective is to face the problem and discover the weaknesses in the management systems that permitted the problem to occur in the first place. The output of an 8D process is an 8D report.
The steps in 8D Report are also called “disciplines,” hence the name 8D Report. The steps are:
1D: Team Formation
8D procedures are used for solving exact problems. The approach is based on a team working together to solve a problem. Teamwork must be coordinated and guided. The team should include only competent persons actively involved in the process and who have been assigned a task or responsibility in subsequent steps. Efficient teams are usually not big.
2D: Problem Description
The more clearly the problem is defined the more likely it will be resolved. Problem solving must be based on facts, not opinions. It is important to clarify the issue type, what is wrong, when did it happen, how big the failure extent is and how many times has it happened. The description must be specific and easy to understand. If possible, a supposed cause should be specified. A complete problem description offers the team directions to solve the problem and helps them prioritize tasks. For example, the fact that defective products were already sent to a customer is very important in deciding which containment actions to take and in prioritizing those actions.
Good description is a foundation for later problem solving.
3D: Interim Containment Actions
In this 8D Report step we try to limit the problem extent and protect our customer. Interim containment actions are a “first aid” that protects the customer from the problem until we define the root cause and implement permanent corrective actions.
Containment actions must not introduce any new problems. They have to be carefully documented with precise information (product codes, lot numbers, dates, etc.). This information can then be used to verify effectiveness of performed actions.
4D: Root Cause Analysis
To effectively prevent a problem from occurring again we have to find the root cause of this problem and remove it. In rare situations there could be more than one root cause. To identify the root cause, a systematic and well-documented analysis is needed. Each possible cause should be tested against the problem description and test data. Root cause is often hidden by other causes and can be hard to find. There are many methods that can be used during the analysis. For example, is /is not, 5 Whys, Ishikawa Fishbone and others.
5D: Corrective Actions
The goal of corrective actions is to remove the root cause and prevent the problem from ever happening again. If good corrective actions have been taken we should never have to write another 8D report for this problem. In this step we are concentrated on a specific event or problem that has already arisen.
The corrective actions have to be carefully documented. For each action a responsible person should be identified and the date when the action is planned to be implemented should be selected. When an action has been finished the actual date of implementation and results should be recorded.
For each root cause identified there are usually many corrective actions needed.
6D: Verification of Corrective Actions
The purpose of this 8D Report step is to verify if the actions taken in step 5D have removed the root cause. If we discover that the root cause has not been completely removed, then we have to point out additional measures. It is sometimes necessary to return to root cause analysis in step 4D and repeat the cycle.
7D: Preventive Actions
At first glance this step is very similar to step 5D . The difference between these two steps in 8D Report is in the reason why we perform them and in final goal. Actions in step 5D are meant to prevent an existing problem from happening again. In contrast, preventive actions remove causes for a potential problem and prevent it from ever happening. 7D actions are proactive and oriented towards a potential event in the future.
Actions are usually based on results of FMEA analysis or observations of negative trends. Often, concrete problems encourage us to think about other problems that could arise on the same product or about the same problem arising on another product or process.
8D: Team and individual recognition
At the end of an 8D process is the time to recognize the team efforts and special team member contributions. This is also a good point to document lessons learned.
This is a chance for the Champion to express thanks to those who have helped in dealing with this problem.