A Disciplined Approach

Perform corrective actions using the 8D model

by W. Frazier Pruitt

Nothing causes anxiety for a team quite like the release of a corrective action preventive action (CAPA) system and accompanying eight disciplines (8D) model. Questions of value come immediately and consistently. The denial phase is inevitable, but the team can accelerate the progression of forming, storming and norming, and emerge performing with a strategy.

Reassure your team that it can easily perform 8D—all that must be done is fit routine problem solving into the eight disciplines. It’s only formatting a framework to organize ideas and remember important steps.

Follow this step-by-step explanation of 8D to reassure your team and get results:

D0: Plan. Write down the original problem, which usually is a customer complaint. Evaluate the time, people and other resources needed to solve and correct the issue.

D1: Use a team. Don’t go it alone—the project results will be better if you form a team. Choose members with diverse skill sets who come from different business functions. Like all problem-solving approaches, teamwork makes solutions more targeted and robust, thus solving the problem from the human, financial and technical perspectives.

D2: Define and describe the problem. Defining the issue sets the scope of your problem. Often, original problem statements are vague or even inaccurate. Correct this by using your team’s specific industry knowledge to clarify and determine the real problem. Writing a good problem statement is worth the effort. Understanding the project will reduce scope creep and keep the team on task.

D3: Develop and execute an interim containment plan. Protect customers from any further effect by establishing a temporary solution to contain the problem.

D4: Determine, identify and verify root causes. This is a critical step. Beware of people who come with causes—or worse, solutions—in hand. The key is to find the root cause using quality tools, such as a three-legged five whys or cause map. The tools organize data and facilitate knowledge sharing. Plus, you might find a fundamental flaw or catch a detail you may have otherwise glanced over.

D5: Choose and verify permanent corrections. This is the step at which people try to begin the 8D process. Resist the “Don’t just stand there, do something” mentality. Hold your judgments and actions until steps D0 through D4 are complete. The solution must be permanent, systemic and address the root cause; the team must understand the problem and root causes before this can be done.

D6: Implement and validate corrective actions. Don’t just verify that the actions are complete—also validate them. Occasionally, corrective actions evaporate into the ether, but it is far better to verify that the action caused an improvement. Measuring improvement will verify not only execution, but also effectiveness. Avoid speculation by using objective evidence, such as graphing variations, hitting a goal three months in a row or using a T-test for statistical proof.

D7: Take preventive measures. Keep the problem from happening in the future. This, justifiably, is the difficult part of 8D. Look for systemic failings and look beyond the current issues. Correct the potential issue for different product lines or departments.

D8: Congratulate your team. Recognize team members by demonstrating your appreciation of them and their contributions. If this is challenging, default to buying the team lunch, but something more meaningful is better. Don’t underestimate recognition—it may be the single most important part of creating acceptance of the 8D and CAPA system.

W. Frazier Pruitt is a senior engineer and quality assurance supervisor at Southco Inc. in the Rochester, NY, area. He earned a bachelor’s degree in electrical mechanical engineering from the Rochester Institute of Technology. Pruitt is an MBA candidate at the Kelley School of Business at Indiana University in Bloomington, and the Alliance Manchester Business School in the United Kingdom. A senior member of ASQ, Pruitt is an ASQ-certified quality engineer and Six Sigma Black Belt.

I recognize your as well as anyone's right to use the terminology you want, but the use of correct terminology is important. Because the opposite reduces mutual understanding and thus makes cooperation much more difficult. You save some verses, but you spend plenty of precious time.
Let's realize that collaborating OEMs, suppliers and laboratories can be situated thousands miles away.
My subordinates, collaborators or students clearly distinguish between nonconformity/defect, correction, rework, regrade and repair that are related to product versus root cause, corrective action, Ishikawa diagram that are related to process.
Thus they save a lot of time because they do not move in vicious circles, e.g. they do not look for root cause in the product because it only occurs in the process, or they are not drawing the Ishikawa diagram until the source process is known, since the Ishikawa diagram typically serves to analyze the process, not to analyze the product.
Finally, I want to note without any offense that the terminology in your article as well as in the ASQ source is not consistent and undoubtedly makes quality problems solving more difficult. (For example, the point ″D5: Choose and verify permanent corrections (PCs) for problem/nonconformity″ in the ASQ source is very confusing in this sense.)

--Ondrej, 05-16-2019

Thank you for your comments. You are no doubt right that ‘corrective action’ is less ambiguous given the support of ISO 9000:2015. In this instance however, ‘permanent corrections’ is used to aid individuals less verses in our quality jargon and the definitions in reference documents. The article also states “The solution must be permanent, systemic and address the root cause”. The words ‘systemic’ and ‘address the root cause’ together with ‘permanent’, sufficiently define the articles use of ‘permanent corrections’ consistent with the expectations of D5. Additionally, the use of ‘permanent correction’ for D5 is supported by tradition and other ASQ resources regarding 8Ds. See https://asq.org/quality-resources/eight-disciplines-8d.

--W. Frazier Pruitt, 05-15-2019

I would recommend the author to follow the ISO 9000:2015 standard that defines the corrective action (3.12.2) as an action to eliminate the cause of a nonconformity and to prevent recurrence, while the correction (3.12.3) is defined as an action to eliminate a detected nonconformity.
Consequently, the corrective action deals with a root cause and therefore it concerns a process, while the correction deals with a nonconformity and therefore it concerns a product. A correction can be, for example, rework or regrade of the product.
Therefore, the terms corrective action and correction cannot be arbitrarily interchanged.
In addition, the adjective "permanent" regarding corrective action as well as correction is just an illusion. In quality, nothing is permanent, but quality means a day-to-day struggle for customer satisfaction.
--Ondrej, 05-13-2019

I would like to ask the author what do the permanent corrections mean?
--Ondrej, 05-03-2019

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