Business statistics | Lean Six Sigma, Six Sigma Certification

As we all know that there are different levels of certification in Lean Six Sigma and these levels have been associated with “Belt” titles. It’s a very obvious question that why the levels here have been associated with the titles used in Martial Arts? That is because of the association of discipline and rigor in Lean Six Sigma similar to the martial arts.
You would find four commonly used belt titles in Six Sigma Certification and they are Yellow Belt, Green Belt, Black Belt and Master Black Belt. However, the most basic level in Lean Six Sigma is sometimes called as “White Belt”. A White Belt understands the theoretical aspects but virtually no application knowledge of the Lean Six Sigma concept. One could say this is an entry level awareness program. Let us understand one by one, the four belts mentioned above.

  1. Yellow Belt: A Yellow Belt is someone who has undergone a basic training program that is may be a day’s training with a basic level of understanding of the quantitative part of the concept. He or she is able to appreciate the goals of Lean Six Sigma. Having knowledge of Yellow Belt level means that person is able to apply basic tools in the company and undertake simple improvement projects. Usually the organization who wants to implement Lean Six Sigma wants all their employees to be at least Yellow Belt trained as this makes the implementation and change management easier and faster.


  1. Green Belt: Lean Six Sigma Green Belt receives a training of at least one week with emphasis on DMAIC method and tools. DMAIC is problem solving methodology which stands for Define, Measure, Analyze, Improve, and Control through which he/she is able to undertake improvement projects in his/her process which improves customer satisfaction and efficiency of the process. Green Belts are also called as “Work Horses” having the following responsibilities:
  • Initial analysis of company like Gemba Walk and Data Analysis which will be helpful in defining the road map of the project.
  • Define the project and prepare the project charter.
  • All over co-ordination with management, yellow belts, black belts and master black belts.
  • Facilitate the team through all phases of the project.
  • Provide training to the team for effectiveness of the implementation.


  1. Black Belt: A black belt is someone who receives at least 3 to 4 weeks of extensive training with the emphases on DMAIC method and tools which is explained as above. Unlike a green belt, black belt is a full time role who has the responsibility to run large scale high impact improvement projects where he mentors and coaches green belts. Responsibilities of a black belt are listed as under:
  • Helps in deciding the project.
  • Helps in refining the project charter and makes sure that the things are moving in the desired direction.
  • Leads, mentors and coaches green and yellow belts and champions.
  • Empowers the team members to design experiments and analyse the data required for the project.
  • Provide training in tools and team functions to project team members.
  • Makes sure that the project succeeds.
  • Maintains balance between Management, Employees and Customer’s needs.
  • Manages the team for effectiveness and efficiency.


  1. Master Black Belt: It is usually a leadership role having excellent change management skills along with having good technical knowledge. After completion of the black belt course and having good experience he/she receives additional 3 to four weeks of training mostly around change management and statistics. MBB’s primary role is to deploy six sigma concepts in the organization, advice to executives or business unit managers, and leverages, his/her skills with projects that are led by black belts and green belts. A Master Black Belt reports the senior or top management and coaches the black belts and Green Belts. Responsibilities of Master Black Belts are enumerated as under:
  • Provides guidance to senior executives and top level managers on Six Sigma management.
  • Help identify and prioritize key project areas in keeping with strategic initiatives.
  • Continually improve and innovate the organization’s Six Sigma process.
  • Apply Six Sigma across both operations and transactions-based processes such as Sales, HR, IT, Facility Management, etc.

If you want to start your journey in Lean Six Sigma, its best you start by understanding some of the basics of Lean Six Sigma. Our Lean Six Sigma Primer Course is Free and it gives a great deal of information on Six Sigma. From there on you could more to Yellow Belt and Green Belt. This approach is pragmatic because it optimizes your investment of resources, time and effort.


As a business analyst you are often expected to act as a bridge between a functional domain and the business stakeholders. Business analysts must be great verbal and written communicators, tactful diplomats, problem solvers, thinkers and analyzers. Though you have been extensive training in project management and related areas, using systematic business and management tools such as graphical analysis, data distribution & visualization, statistical discovery, etc are considered to be difficult by many Business Analysts.
Fortunately Lean Six Sigma, which is process improvement methodology provides many of the tools that can  be handy for Business Analysts at one place. It comprises of statistical tools and techniques along with visualization tools.  There are many tools such as Visual Analysis & Data Discovery tools like Fish-bone, 5 why, in scope-Out scope, Box plots and analytical tools like MSA, Descriptive Statistics, Variation, Correlation and Regression. They are explained in brief as under:
Visual Tools:
There are many tools which a business analyst will learn from Lean Six Sigma Green Belt Certification. We’ll talk about few Visual analysis tools from Lean Six Sigma in brief as under:

  • Fish Bone Diagram also called as Cause and Effect Diagram helps to reach the root cause of any business issue. The important characteristic of this tool is to categorize the issue into 6 different aspects like Men, Machine, Material, Measurement, Method and Mother Nature (Environment). This will help the analyst prioritize the problem and solve the problem in a systematic manner.
  • Another tool for root cause analysis is 5-Why which involves repeating the question “Why” where each question forms the base of the next question and this will go on until the root cause is found. All the questions and answers of the 5 Why, are placed on a sheet of paper with the help of which the analyst can view the whole picture in a single page.
  • Box plot is a quick way of visualization of data and is represented in the form of box & whiskers. It helps in scrutinizing and comparing sets of data which demonstrates the variation in the sample data set.
  • Statistical process control (SPC) is method of measuring and controlling KPIs of any process. AKA control charts, this helps to proactively identify issues from data. It is a great tool for continuous monitoring of process parameters both in service and manufacturing processes.
  • Run charts are similar to control charts and suggest shifts in the process over a period of time and points out special factors which influence the process variability.
  • FMEA stands for Failure Modes and Effect Analysis which is an approach to identify all possible failures in any process. Like doing analysis of how and where we can fail so as to take precaution before even starting the implementation of any project. This is a very important element for the success of any project which will help a business analyst in his/her daily management.

Analytical Tools:
Here are few examples of data discovery analytical tools that a Business Analyst will learn from Six Sigma.

  • Quite often Business Analysts struggle with poor data quality. MSA aka Measurement System Analysis is a Lean Six Sigma tool  used to evaluate that whether the data collection method, the instruments/source used for measuring and whole measurement is precise & accurate or not. This is also used to ensure the integrity of data used for analysis and gauge the effects of errors in measurement used to make decisions taken for product or processes.
  • Descriptive statistics includes the assessment of central tendency and measures of dispersion in the any data set. Further it helps to identify skewness, kurtosis, outliers, and specific patterns in the distribution.
  • Analysis of Variance abstracted as ANOVA is a statistical hypothesis test used to identify significant factors that cause a particular business issue. The biggest the merit of such advanced statistical methods is in confidence & credibility that a Business Analyst can provide to the leadership and management on his analysis and conclusions.
  • Correlation & Regression are similar tools used to establish a relationship between the two business variables such as revenue and capacity. By validating such relationships, the Business Analyst can bring out significant insights to the management.

A business analyst having Green Belt Certification shall have a comprehensive understanding of Lean six sigma and shall be able to apply its tenets to their daily work. The principles of Six Sigma are so widely applicable that employees getting trained are highly valued and aggressively sought after. Lean Six Sigma Certification will be a stepping stone for professionals to a higher level as you avail expertise in different problem solving tools and techniques of Lean Six Sigma.


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Have you ever thought about this before – Will Six Sigma help me become a better leader? Isn’t leadership a soft skill unlike Six Sigma? Six Sigma is more about playing with numbers, statistics, Minitab!!!
Ask leaders of organizations that follow Six Sigma as a management philosophy, and they will disagree.

A true practitioner of Six Sigma is a great leader. All basic principles of Six Sigma help to be a better leader:

  • Customer Centricity
  • Data or Fact Based Decision Making
  • Strong Process Orientation
  • Structured way to improve, design and sustain processes

Let’s consider 4 important dimensions of leadership that most world class organizations strive to instil in their associates.

  • Ability to grow the business
  • Capability to lead the team to deliver
  • Drive culture of execution
  • Conviction to sustain the momentum & optimism

Let us consider one at a time, and understand how Six Sigma can help focus on these 4 aspects.

Ability to grow the business

  • Deep and broad business perspective is the first and foremost pre-requisite for any leader to growth their business.  They have the ability to fragment or aggregate processes/tasks, and develop a meaningful understanding. Good leaders are quick to break complex processes into simple & small units, and manage them effectively. We call this ability as Strong Process Orientation in Six Sigma.
  • Good leaders challenge the status quo, and thereby reinvent the business. Availability of information & factual data empowers a leader to take bold decisions.
  • Businesses that are customer centric grow faster . Moreover customer requirements constantly change. Ability to choose the right method to reach out to customer, ask the right questions and present the data appropriately is the key. In other words, good leaders take additional care to establish and manage Voice of Customer programs.
  • Customer retention and repeat business is all about instilling higher internal standards and practices to make processes error-free or defect-free.

 Capability to lead the team to deliver

  • In order to retain great talent, a leader should be able to align functional goals to individual’s KPI’s. They should use data to differentiate high and poor performers rather than intuition and gut feeling.
  • A good leader’s ability to communicate crisply and candidly is only possible when they are data centric.

 Drive Culture of Execution

  • Results need to consistent. Great leaders manage variation along with averages. One of the primary goals of Six Sigma is to reduce Variation.
  • Data or fact based decisions result in high probability of success. This means more confidence about the team and better alignment.

 Conviction to sustain the momentum & optimism

  • Constantly raising the bar is possible when one understands the CTQs, key drivers of the business, and process capability very well.
  • Displaying personal courage cannot come without confidence. And confidence comes only with data.

So a good leader will not miss a single opportunity to apply the above principles of Six Sigma in their business to deliver results consistently.
That is why at many world class organizations, Six Sigma is in the fabric of who they are. So, beyond doubt, Six Sigma help me become a better leader!


Here are my observations based on not just training a few hundred Six Sigma Green Belts across different demographics of geography, industry and age group, but also having mentored them for few months after the training:

  • Retention of a subject like Six Sigma is much less than soft-skills or technical training like software languages.
  • Ability of Green Belts to relate the application of six sigma concepts to their line of business is quite lesser than soft-skills like team work, time management, negotiation skills, etc.

Here are the 10 things according to me that Six Sigma Green Belts forget within just 10 -days of attending a training program, implying nearly zero retention:

  1. Project Charter: How to a write a business case that convinces the management? And also differentiate it from Problem Statement.
  2. Fish-Bone: What to do after completing a Fish-Bone diagram? Of course, collect data but on what factors?
  3. Gage R&R: Conduct an live Gage R&R study (at least Discrete data).
  4. Sampling: Choosing a sampling scheme and deciding the sample size for data collection.
  5. Descriptive Statistics: Meaningful and practical interpretation of ‘Standard Deviation’. If there is a process with Standard Deviation of 5 minutes, what does this number mean in real sense?
  6. P-value: What does it mean to the business to accept or reject a hypothesis based on P value?
  7. Variation: Identify the major sources of variation that impact a project metric?
  8. Regression: How to use the regression equation to operate the business efficiently.
  9. Control Chart: Explain to a layman (probably a Manager) what an out-of-control data point means in practical sense.
  10. Sustenance: How to make sure the project exists after a year. I don’t mean the project deck! Many times, it is considered that sustenance is not in our hands, but actually it is a skill that can be acquired and needs to be taught to all Green Belts.

One of the primary reasons, why Green Belts can’t retain these 10 things, is because most of all this is taught in less than a week with little time for things to settle in, and for the participants to relate.
One of the solutions, that works well for me as a coach, is to limit the class size to 2 or 3 and spread the program over 60 days. I actually found best results  during my one-on-one training sessions!
Return-on-Investment of such executive development programs are at most important and so the business & career benefits recoups these investments.
My note will be incomplete if I don’t mention about few things that Six Sigma Green Belt retain very well after the training, even for several years:
· How to do Fish-Bone Diagram?
· How to play the Gage R&R game?
· Remember and recite the phrase “P is low, Null must go”
· How to map the process?
· What is Value Add, and Non-Value Add?


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