8D Problem Solving and Root Cause Analysis


August 1, 2022
By Darren Dolcemascolo

One popular approach to problem solving and root cause analysis is 8D.   The 8D process has gained popularity over time because it is one that is often requested of suppliers when a failure occurs (or recurs often).  8D Problem Solving is a team based approach to identifying and eliminating the root cause of a recurring problem.  While the A3 approach can be used for making an improvement from current to target condition or for returning to a standard condition, the 8D approach is primarily used for returning to a standard condition.  What is the 8D problem solving approach?  Let's examine each Discipline- that's what the "D" stands for in 8D.

Discipline 1:  Form a team.  Complex problems are best solved by working in teams.  While one person can solve problems, it is much more likely that a leveraging a team will result in a better result that has buy-in.  In this step, team members and their roles are selected.  Roles might include subject matter experts, facilitator/team leader, outside eyes, customer representative, supplier representitive, etc.

Disciple 2: Define the problem.  We have written much about problem solving and how to define a problem We might think of a problem as the gap between the current condition and a target condition or a standard.  In 8D problem solving, we are usually talking about the gap between a current condition and a standard.  In order to properly define a problem for 8D Root Cause Analysis, we need to gather as much information as we can about the problem through observation and data collection.  Asking and answering questions is helpful:

  1. Who?  Who observed the problem?  Who is affected by the problem?
  2. What?  What type of problem is it?  What has the problem?  What is happening?
  3. When?  When was the problem first discovered?  When has it been observed since?
  4. Where?  Where was the problem discovered?  Where does the problem occur?
  5. Why?  Why is it a problem?  (NOTE: We do not ask why it happens to discover the cause at this point- that happens later in the problem solving process)
  6. How Much / How Many?  How much is the problem costing us in time, dollars, etc.?  How many times has it occurred?
  7. How Often?  How often does the problem occur?  Is there a trend?  Can we quantify this?

Discipline 3: Interim Containment Actions.  What actions can we take to prevent the problem from escaping to the customer?  Note that this is not solving the problem or addressing the root cause.  These are temporary fixes that we put in place until we solve the problem to its root cause.  All too often I find that clients have added layers of checking/inspection to their processes as a means to prevent escapes.  These layers of inspection remain for many years in most cases.  Instead, these should be very temporary.

Discipline 4: Determine the root cause.  Using tools such as the 5 Why's approach, we need to determine the true cause to our problem.  The 5 Why's approach involves asking and answering the question "why?" repeatedly until we find the root cause.  This sounds simple, but it requires actually going to the gemba and seeing what is happening in order to properly answer the "Why" question.  Whenever we ask "why?" we want to answer with the immediate cause.  To learn more about the 5 Why approach, view our OpEx Minute video "How to Use the 5 Why's."   To learn more about tools for gap analysis such as the Fishbone Diagram and Pareto Analysis, read our article on root cause analysis

Discipline 5: Identify Permanent Corrective Actions / Countermeasures.  This is where we address the root cause.  We recommend developing several alternative solutions through brainstorming within the team, and then using experimentation/pilot testing and tools such as criteria matrices to select the best possible solution.  To read more about tools for determining corrective actions, read our article on countermeasures to address root causes.

Discipline 6: Validate/Test Permanent Corrective Actions / Countermeasures.  As we implement our permanent corrective action(s), we test.  We want to ensure that what we have put into place actually eliminated the root cause.  After confirming this, we are almost done.

Discipline 7: Prevention/Standardization/Spread.  We put in place long term measures for preventing this problem from recurring.   How do we ensure that our corrective actions are going to continue to work?  Will we monitor and audit the process?  What kind of training and documentation will we put in place going forward?  Can/should our corrective actions be utilized in other similar areas/processes?

Discipline 8: Congratulate the Team / Celebrate.  We should always remember to celebrate successes.  If a team has properly gone through the 8D process and truly solved a problem to its root cause, it is time to celebrate.

 

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