8 Disciplines to identify, correct, and eliminate errors29 Sep 21
GIRI board member Helen Soulou explains how to use the 8 Discipline problem-solving method to identify, correct, and eliminate recurring errors.
A tool that was originally developed at Ford to facilitate problem solving as a team is now one of the most widely-used processes for solving complex problems both in the automotive industry and across many others. The 8 Discipline problem solving tool, now known as Global 8D, is particularly applicable to quality management.
GIRI has created a downloadable toolkit through which the 8Ds can be used to establish root causes of errors and enable appropriate preventative actions to be identified so that problems will not recur.
D0. Planning and emergency response
An initial planning stage (D0) was added when the 8D system was revised, which focuses on any emergency actions required before initiating the 8Ds, and basic planning for how you will manage the process.
D1: Form a team
The 8D method is a team problem-solving tool, therefore you need to gather a (small) team of relevant, competent people and list them on the front page of your toolkit.
“Forming a team is not simple,” says Helen. “You need some core members but you also need to think about other disciplines that will be involved and people who will contribute information at different stages, such as designers who may need to provide design solutions – a team is a live thing. Some members will be core to the entire process; others will join and leave as the 8D process progresses.”
D2: Define the problem
The ‘is and is not’ analysis helps identify the limits of the problem; who is affected by it, and who could be affected by it but isn’t; why the problem is a problem, and why it is not a problem; when the problem appeared, and when it could have appeared but didn’t, etc.
“The process makes you think about the parameters of the problem,” says Helen, “and what may have occurred before the problem. It makes you think about timing, where the problem happened, how widespread it is, and how often it is occurring. Is it increasing or decreasing? It is very important to determine the problem correctly.”
D3: Interim containment actions
Once you have defined the problem, you can start to understand the interim actions you need to put in place to contain the problem while the 8D process continues. Define potential actions, verify these will work and record them in the 8D toolkit. Then track the actions to make sure they are implemented and that they are effective.
“Lots of people want to jump straight into the solution, but if you study the problem you have a better understanding of the containment actions required,” says Helen. “You could, for example, think that the problem is one loose bolt in one joint, but then realise it affects many joints, which means your containment action needs to be more widespread.”
D4: Identify and verify root causes
Once you have contained the problem, you can focus on root cause analysis. Tools to use here include the Fishbone diagram, a visual brainstorming tool that can help to identify all the likely root causes of a problem in a structured way. Another technique is the ‘Five Whys’, an interrogative technique that asks why a problem has occurred, with each answer leading to the next question until you arrive at the root cause. Other techniques such as process mapping can also be used.
“Once you have identified and documented potential root causes, you need to verify and evaluate the root causes," says Helen. "Using your ‘is and is not’ analysis, you can test whether your identified root cause gives you a clear understanding of why the problem happened in the ‘is’ column, and why it hasn’t happened in the ‘is not’ column. Another way to verify your root cause is by trying to replicate the problem. Put the conditions in place and see if the problem is repeated.”
D5: Identify and verify permanent correction actions
Once you have identified the correct root cause, you can move onto prevention and corrective actions. This involves developing and choosing the most appropriate corrective actions to ensure that the problem will not recur, and verifying that your solution will solve the problem without causing any knock-on issues.
D6: Implement and validate correction actions
Put your corrective actions into action and make sure these work. If you have identified the correct root cause and the most appropriate corrective action, the problem should be eliminated and it should be possible to remove the initial containment actions. If the problem is not completely resolved, go back to step four.
Identify a person responsible for implementing each corrective action and record this in your toolkit along with the date the action was taken. Helen suggests revisiting the issue after six months to check that everything is still in order.
D7: Prevent the problem recurring
This is the point at which you review your systems and procedures in light of what you have learned to ensure that this issue and others like it don’t happen again. Proactively make the changes that are found to be necessary to achieve this.
Recognition of the contribution of both the team and its individual members is an important aspect of the 8D process. This is also the point at which you should document the lessons learned and share this learning more widely.
The GIRI website has lots of free resources to aid understanding of how and why errors occur and how to avoid them.
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