articleKaizenLeanSix Sigma

Root Cause to Solution Identification Simplified

By John Knotts Updated on October 4th, 2022

The one thing that differentiates process improvement projects from regular projects and project management is the methodical way a process improvement practitioner arrives at the root cause and then devises solutions or countermeasures to combat that root cause.  In a normal project, the “solution” is already known and the project exists to implement that solution.

This is one of the most challenging aspects of process improvement that many certification students face.  It starts with a clear problem statement that does not address symptoms — it only outlines the problem.  Even when we already have a good idea of what might be happening, we have to start a process improvement project with our eyes wide open.

Throughout Gemba Academy’s courses, there are several quantitative (inferential statistics, statistical process control, analysis of variances, etc.) methods to help identify the root cause. Also, there are several brainstorming-based approaches with formalized tools, such as 5 Whys and the Fishbone Diagram.  However, there is a simpler way to get to the root cause and determine what to do about it.

Key Concepts

This approach uses four simple key concepts, called Divergent to Convergent Thinking, Silent Brainstorming, Affinity Diagraming, and Tree Diagraming. Using these approaches, you can quickly determine the root causes of a problem and identify potential solutions.  Let us examine each of these four concepts before discussing the approach that brings them all together.

Divergent to Convergent Thinking

Divergent thinking is where you are trying to get as many ideas as possible.  Convergent thinking is where you take all these ideas and bring them down to a few or one main idea.

Silent Brainstorming

Silent brainstorming is a brainstorming approach that generates a lot of ideas very quickly, while everyone remains quiet.  This allows all the participants to come up with ideas without distractions or influence from other members of the group.  Silent brainstorming combats problems such as groupthink, undue influence, and social loafing, which are all common in traditional brainstorming sessions.

To conduct silent brainstorming, give everyone participating a pack of 3 by 5 sticky notes (I like using the super sticky kind). Give the participants a problem or phrase and instruct them to respond to the item shared by writing one thought per sticky note.  They are to write down as many ideas or thoughts as possible in a set time (10, 30, or 60 minutes, depending on the expected amount of responses).  As the participants are completing their sticky notes, the facilitator(s) are gathering them up.

Affinity Diagraming

Affinity diagraming organizes a large number of ideas into natural relationships or groups.  This is the organization of an unorganized brainstorming session.  We use affinity diagramming to generate, organize, and consolidate information related to a product, process, complex issue, or problem.  Typically, we are “affinitizing all the like ideas into natural groups.”

Tree Diagraming

Like a file structure on a computer, the larger affinity groups can be further grouped (or affinitized) into larger entities.  This is called tree diagraming.  It helps us further refine a large number of ideas into a few major concepts.

The Approach

Using divergent and convergent thinking, coupled with silent brainstorming, affinity diagraming, and tree diagraming, we can quickly move from a problem statement to root causes to solutions.

Bring all the participants into an event.  Present them with the specific problem statement and what you have learned about the problem.  Give the participants 10, 30, or 60 minutes to generate as many possible causes of the problem as possible.  As they silently brainstorm these ideas, affinitize (i.e., group) them on the walls of the room.  Once time is up, have the participants validate your groupings (no ideas can be removed).  With the help of the participants, come up with a name that represents each of the affinitized groups.  Then, if you have several groups, look for larger groups that these can be tree diagramed into.  Name these larger groups.  These are your root causes.  Using multi-voting or another prioritization technique, determine which is the largest or most likely root cause.

With this one root cause in hand, use the exact same approach to seek out potential solutions to that root cause.  Then, using affinity and tree diagraming, you can again quickly get to a short list of potential solutions or countermeasures.  Again, using your preferred prioritization approach, you can select at least one solution that you want to implement.

By using this simplified approach, you can quickly capture a great deal of information and ideas and get to a very specific solution to a process improvement problem.

  1. Alyssa Figarsky

    September 14, 2022 - 12:35 am

    Hi John, I’m currently working on an assignment for my Green Belt course and this post really grabbed my attention. Soon I will be forming a group, defining a problem, and performing root cause analysis. Honestly, I saw that you mentioned the 5 Whys and I thought, “How could it get more simple than that?” After reading through your 4 concept process I am absolutely intrigued. First, silent brainstorming to get as many ideas as possible on the board, then the 2 diagrams to refine. Going through the process of divergent to convergent thinking twice to determine both root causes and solutions does seem efficient in theory. I can picture how this approach would allow more thought and more ideas when compared to the 5 Whys. After considering your process, I think the 5 Whys may be too narrow or rigid, unaccommodating of multiple perspectives. I am looking forward to sharing this approach with my future teammates and I’m hopeful that we can try it out for ourselves.

  2. Austin Morrocco

    September 14, 2022 - 3:11 pm

    After reading this article, I found it very intriguing and exciting. In my next project, I want to try these methods. I think each of them can be very useful in finding and determining the root cause of a problem. It seems that by using this approach, there could be fewer problems you might run into while determining the root cause. This approach also seems less complicated and seems like there is less room for errors. I like that this method is fast and easy to follow. Are there any recommendations you might have for starting out? How would implementing this way of problem-solving in a group go smoothly?

  3. Mike B.

    September 20, 2022 - 11:14 am

    Thank you, John for sharing this method for a “simple” root cause and solution identification! Before I give this a try on my next engagement, could you help me understand how a “grouping” of causes is the “root” cause? I’m not entirely bought into the Group = Root premise (that’s not how my affinity diagrams have turned out in the past). Short of this disconnect, I do love the simplicity of this approach!

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