What’s the difference between Six Sigma and Lean Six Sigma

When starting down the journey of Six Sigma, learning all of the different terms and abbreviations can be daunting.  The same goes for Six Sigma certification, and the many different options that are available.  One question we hear a lot at the Management and Strategy Institute is “What’s the difference between Six Sigma and Lean Six Sigma?”

In this article, we’ll break down the primary differences between both to help you better understand them.  We’ll also try to help you understand which certification may best fit your needs.

At their heart, both Six Sigma and Lean are process improvement methodologies.  One focuses on the analyzing of processes and removing defects while the other focuses more on waste reduction.  Because both methodologies work to accomplish similar tasks, they are often used in conjunction with each other.  Initially, these methods where used almost exclusively in the manufacturing sector.  This is where the processes where developed and they were a natural fit.

As time has gone on however, many other industries have discovered that Six Sigma and Lean can aid their organizations in saving money and improving processes.  Now industries such as Healthcare, Information Technology, and even Federal and State governments are using “Lean Six Sigma” principles.

Lets take a very brief look at the two methods separately.  We’ll start by discussing Six Sigma and the steps it uses to improve processes within an organization.

Six Sigma

Six Sigma’s aim is to eliminate waste and inefficiency, thereby increasing customer satisfaction by delivering what the customer is expecting.  It is a highly-disciplined process that helps us focus on developing and delivering near-perfect products and services.
The word Sigma is a statistical term that measures how far a given process deviates from perfection.  The central idea behind Six Sigma is that if you can measure how many defects you have in a process, you can systematically figure out how to eliminate them and get as close to “zero defects” as possible.

There are five basic steps to a Six Sigma project.  These are referred to as the D.M.A.I.C method.  That stands for Define, Measure, Analyze, Improve, and Control.  D.M.A.I.C is an approach to problem-solving and a tool for improving an existing process.


A Lean company is disciplined and dedicated to achieving optimum performance with the lowest or least amount of effort and energy.  As a term in business, Lean has a broad-based customer focus that concentrates on providing more to the customer.  It does this by supplying the product that is just what the customer needs, when needed, in just the right amounts and for the right price, using the minimum materials, equipment, workspace, labor resource, and time.

The whole concept of Lean is focused on the removal of any unnecessary waste from the production process.  It focuses on producing a high quality output.

The core activity in examining any Lean process is to:
•    Map out the current components 
•    Identify which elements are waste
•    Change or improve those wasteful elements and construct a new or improved process that is leaner

What Should You Do First? Lean or Six Sigma?

When deciding on improving performance, we are often asked what program should be done first. Six Sigma Certification deals with a process, whereas Lean Certification teaches a multitude of methods and creates a cohesive approach to customer-driven operations. Since Six Sigma could be considered a tool to help implement the Lean process, it will be of better benefit to begin learning Lean rather than Six Sigma.

When a company tries to address issues with the Six Sigma process, it is akin to going to a golf course with only a driver and expecting to play well with that single club. Six Sigma is a tool in your business’s arsenal that can be utilized to eliminate redundancies in your company processes, thus reducing wasted time and bettering the customer experience. Yet, if Six Sigma is implemented prior to Lean, your business might attempt to improve a particular process that is already performing optimally or might not be needed at all.

Lean Certification will provide your business with an overall understanding of why customer-driven processes should be improved or eliminated to better customer experience and reduce wasted time. Imagine being given a complex tool and not having instructions on how to use it. Now, view the tool like Six Sigma and the instructions as Lean. Without Lean, it isn’t easy to use Six Sigma in a way that will ultimately lead to a more efficient and effective business structure.

Another important consideration is that Lean Six Sigma isn’t just one certification, it is broken down into specific roles, or belts.  We’ll discuss this more in the Putting Lean and Six Sigma Together section below.  For now, keep in mind that the Six Sigma Yellow Belt, Green Belt, and Black Belt all have different roles and considerations.  Deciding to get your Six Sigma Black Belt or Lean Six Sigma Black Belt will be determined by the industry you work in and your goals for the Six Sigma project.

Defining Waste with Six Sigma and Lean

Both Lean Certification and Six Sigma Certification can help identify waste processes within your organization that use up valuable resources and time when trying to address customer needs. Lean Certification will provide your business with a complete analysis and framework of what components of your business structure need improvement. Six Sigma Certification will provide you with insight into particular aspects of your company’s plan and provide you with the knowledge to better those processes.

Lean can be viewed as an overall strategy to adapt your business structure to target general wasteful practices that set back your organization. Six Sigma can identify a subset of those strategies and provide you with information to either eliminate specific processes or change them to accomplish a more customer-driven approach to your operations.

Lean will provide you with in-depth knowledge of the entire process of waste elimination. Six Sigma will help your company refine or eliminate particular aspects of your core business approach. Both courses will give you the ability to better understand the wasteful components of your company’s structure.

Putting Lean and Six Sigma Together, Which Option Is Right for You?

Since these methodologies are so similar, it’s natural that they are used in unison.  Not all industries use “lean” however since it focuses so much on eliminating waste from a process or supply-chain.

If you work in an industry such as Manufacturing, Logistics, Healthcare, Information Technology, or a Government agency, then selecting Lean Six Sigma certification is the most appropriate path.

Choosing between Six Sigma and Lean Six Sigma depends on your specific objectives and organizational needs:

  1. Choose Six Sigma If:
    • Your primary concern is improving product or service quality.
    • You are dealing with processes that have significant variations and defects.
    • Your organization has already implemented Lean principles or has minimal waste-related issues.

  2. Choose Lean Six Sigma If:
    • You want to improve both quality and process efficiency.
    • Your organization struggles with waste, delays, and inefficiencies in its processes.
    • You are looking to create a culture of continuous improvement throughout your organization.

Organizations often opt for Lean Six Sigma because it provides a comprehensive approach that addresses quality and efficiency concerns. However, assessing your specific needs and constraints is important before deciding on the most suitable methodology.

Six Sigma Belts

Six Sigma Belts, which include individuals with different levels of expertise and responsibilities, play a significant role in the decision-making process when choosing between Six Sigma and Lean Six Sigma.

These belts come in various levels, including White BeltsYellow BeltsGreen BeltsBlack Belts, and Master Black Belts, each with specific roles and knowledge levels.  You can learn more about the different belt levels here.

The Management and Strategy Institute is a premier provider of courses and training to better your business and increase your productivity. With our professional development certifications, you will be able to better identify and correct processes that negatively affect your core business strategy.

Selecting which Six Sigma Belt level is most appropriate for you is discussed in another article. For more information about our business development programs and certifications, contact The Management and Strategy Institute today.

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