Six Sigma 6 Steps Of Critical Thinking

The following is a transcript of the infographic above:

Lean Six Sigma is simply a process for solving a problem. It consists of five phases: Define, Measure, Analyze, Improve, & Control. This process is also known as DMAIC (“duh-may-ik”), its acronym.

Phase 1: Define

Define the problem. What problem would you like to fix? The Define Phase is the first phase of the Lean Six Sigma improvement process. In this phase the project team creates a Project Charter, a high-level map of the process and begins to understand the needs of the customers of the process. This is a critical phase in which the team outlines the project focus for themselves and the leadership of the organization.

  1. Define the Problem by Developing a “Problem Statement”
  2. Define the Goal by Developing a “Goal Statement”
  3. Define the Process by Developing Process Maps
  4. Define the Customer and Their Requirements
  5. Inform Others of Project Progress

Phase 2: Measure

Quantify the problem. How does the process currently perform? Or in other words, what is the magnitude of the problem? Measurement is critical throughout the life of the project. As the team starts collecting data they focus on both the process as well as measuring what customers care about. That means initially there are two focuses: reducing lead time or improving quality. In the Measure Phase, the team refines the measurement definitions and determines the current performance or the baseline of the process.

  1. Determine How the Process Currently Performs
  2. Create a Plan to Collect the Data
  3. Ensure the Data is Reliable
  4. Gather the Baseline Data
  5. Update Your Project Charter

Phase 3: Analyze

Identify the cause of the problem. What is causing the problem? The Analyze Phase is often not given enough attention and, without analysis, teams jump to solutions before knowing the true root causes of the issues. The result is teams who implement solutions but don’t resolve the problem! These efforts waste time, consume resources, create more variation and, often cause new problems. The ideal is for teams to brainstorm potential root causes (not solutions), develop hypotheses as to why problems exist and then work to prove or disprove their hypotheses. Verification includes both process analysis and data analysis and has to be completed before implementing solutions. This is the crux of the Analyze Phase!

  1. Closely Examine the Process
  2. Graphically Display the Data
  3. Look for What Might be Causing the Problem
  4. Verify the Cause(s) of the Problem
  5. Update Your Project Charter

Phase 4: Improve

Implement and verify the solution. How will the team mitigate the root causes of the problem? Once the project teams have determined the root causes it’s time to develop solutions. The Improve Phase is where the team brainstorms solutions, pilots process changes, implements solutions and lastly, collects data to confirm there is measurable improvement. A structured improvement effort can lead to innovative and elegant solutions that improve the baseline measure and, ultimately, the customer experience.

  1. Brainstorm Solutions That Might Fix the Problem
  2. Select the Practical Solutions
  3. Develop Maps of Processes Based on Different Solutions
  4. Select the Best Solution(s)
  5. Implement the Solution(s)
  6. Measure to Ensure Improvement

Phase 5: Control

Maintain the solution. How do you sustain the improvement? Now that the process problem is fixed and improvements are in place, the team must ensure that the process maintains the gains. In the Control Phase the team is focused on creating a Monitoring Plan to continue measuring the success of the updated process and developing a Response Plan in case there is a dip in performance. Once in place, the team hands these plans off to the Process Owner for ongoing maintenance.

  1. Ensure the Process Is Properly Managed and Monitored
  2. Document the Improved Process
  3. Apply Improvements to Other Areas
  4. Share and Celebrate Your Success
  5. Continuously Improve the Process Using Lean Principles

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What’s next?

dmaicinstructionslean six sigmastep by step

The last value concept of my new Lean Six Sigma model is called “zhi,” a Chinese term, which means to know or understand.  Confucius believed that for most people, learning was ongoing.  One of the philosophies of Confucianism is that everything a person learns is subject to evaluation and reflection, and it is through this iteration process that people move toward righteousness.  Thus Confucius believed that only a "small man" would not try to think without learning or not reflect on what he has learned.


Critical Reflection and Thinking

In my model, the idea that learning is continuous and is subject to evaluation is not significantly different from other quality management frameworks; however, the concept of reflection is significant.  In particular, I focus on a concept referred to as “critical reflection,” which goes further than the normal definition of reflection. It includes the following four activities as defined by Don Clark (

  1. Assumption analysis – The idea is to think in a way that challenges our own beliefs, values, and social norms;
  2. Contextual analysis – This is a realization that our assumptions are formed based on our personal beliefs and values;
  3. Imaginative speculation – This is conducted by imagining alternative ways of thinking that challenge our beliefs and values;
  4. Reflective Skepticism- The ability to think about a subject in such a way that the evidence is temporarily rejected in order to prove its validity.

In any training or formal education, it is rare that reflection is taught in a sense that instills deeper critical thinking.  In the book that I am currently working on, I will show how the concept of zhi and critical reflection can be utilized throughout an organization. For now, I will demonstrate how to use critical reflection as part of continuous learning, improvement and innovation.  I will demonstrate this concept through the presentation of a fictitious example.


Example of Critical Thinking in Continuous Improvement

Company XYZ has implemented continuous improvement throughout its organization.  It has also implemented the core value of zhi and actively uses critical reflection as a way of conducting assessments and solving problems.  One day, the process owner of the financial management process sees that the order –to-cash process is trending upward beyond the set target of five days.  In fact, the time from order initiation to cash in the bank has been steadily increasing beyond the normal ranges for a few weeks. The process owner determines that this problem can be best resolved by the quality excellence teams.  The quality excellence teams are composed of employees who work on areas throughout the process and are responsible for processing the payments.

The quality excellence team gathers to study the problem.  A facilitator is assigned to the team to assist in critically thinking about the problem.  First, the team brainstorms some possible root causes of the long processing times.  The team may use a technique called the “Five Why” framework in which why is asked up to five times to a problem when stated as a question. By the fifth why, it is expected that the group will have identified a root cause.  An example of the “Five Why” technique is provided below:

  1. Why do we have long processing times?  Because we are making mistakes in processing.
  2. Why are we making mistakes in processing? We are rushed. 
  3. Why are we rushed? We did not anticipate this large number of transactions.
  4. Why did we not anticipate this number of transactions? Because we did not take into account that the company cut its prices by 30%.
  5. Why did we not take into account that the company was cutting prices by 30%?  We never read the memo sent out by communications.

The facilitator then asks probing questions of the quality excellence team to get them to think a little harder about the root cause.  The facilitator asks questions such as, “Have you thought of why you don’t read the company's memos?” “What if you did read the memo? Would you be able to forecast the level of demand accurately?”  The facilitator asks probing questions to encourage critical thinking and reflection.  By doing so, the group realizes that after carefully considering all the options, failing to read the memo was not actually the root cause, it was something else.

The quality excellence team then measures the baseline data to validate its claims or assumptions.  The team continues to ask critical questions to challenge the data and interpretation of the data, such as, “What if we considered X, Y and Z as well?” At the end of collecting the data, the quality excellence team will have critically considered all elements and be able to identify the root cause.  The team, through its assessment, will then consider initiatives or counter measures to eliminate the root causes; again, the team members will use critical thinking to seriously think through their ideas and how to implement them.  They will then implement these ideas and measure the impact of the initiative on processing time, conduct the lessons learned, and report back to the process owner with their evaluation and recommendations.


Concluding Thoughts

As you can see from the example, the critical reflection and thinking enables the team to come up with new, better, and innovative ways to solve a problem.  Critical thinking promotes a deeper learning experience and can dramatically enhance the results of an organization’s continuous improvement strategy.  Do you think incorporating critical reflection and critical thinking into Lean Six Sigma can result in greater results?


By Kyle Toppazzini



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