What Is Six Sigma?

What Is Six Sigma?

Six Sigma – what does it mean?

“Six Sigma is a quality program that, when all is said and done, improves your customer’s experience, lowers your costs, and builds better leaders. — Jack Welch

Six Sigma at many organizations simply means a measure of quality that strives for near perfection. It can be called “Six Sigma,” or it may have a generic or customized name for the organization like “Operational Excellence,” “Zero Defects,” or “Customer Perfection.”

Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects (driving toward six standard deviations between the mean and the nearest specification limit) in any process – from manufacturing to transactional and from product to service.

The statistical representation of Six Sigma describes quantitatively how a process is performing. To achieve Six Sigma — statistically — a process must not produce more than 3.4 defects per million opportunities. A Six Sigma defect is defined as anything outside of customer specifications. A Six Sigma opportunity is then the total quantity of chances for a defect. Process sigma can easily be calculated using a Six Sigma calculator.

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The fundamental objective of the Six Sigma methodology is the implementation of a measurement-based strategy that focuses on process improvement and variation reduction through the application of Six Sigma improvement projects. This is accomplished through the use of two Six Sigma sub-methodologies: DMAIC and DMADV.

The Six Sigma DMAIC process (define, measure, analyze, improve, control) is an improvement system for existing processes falling below specification and looking for incremental improvement.

The Six Sigma DMADV process (define, measure, analyze, design, verify) is an improvement system used to develop new processes or products at Six Sigma quality levels. It can also be employed if a current process requires more than just incremental improvement.

Both Six Sigma processes are executed by Six Sigma Green Belts and Six Sigma Black Belts, and are overseen by Six Sigma Master Black Belts.

According to the Six Sigma Academy, Black Belts save companies approximately $230,000 per project and can complete four to six projects per year. (Given that the average Black Belt salary is $80,000 in the United States, that is a fantastic return on investment.)

General Electric, one of the most successful companies implementing Six Sigma, has estimated benefits on the order of $10 billion during the first five years of implementation. GE first began Six Sigma in 1995 after Motorola and Allied Signal blazed the Six Sigma trail. Since then, thousands of companies around the world have discovered the far reaching benefits of Six Sigma.

Many frameworks exist for implementing the Six Sigma methodology. Six Sigma Consultants all over the world have developed proprietary methodologies for implementing Six Sigma quality, based on the similar change management philosophies and applications of tools.

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Comments 132

  1. sixsigmamarketing

    Good introduction into the basics of Six Sigma.

    Definately worth a read.

  2. muhammad

    it is very useful article because six sigma become the way which all the combany take this way to make money
    thank you for your effort
    best regards

  3. Khushbu

    Thank you for giving me the meaning of this word ”SIX SIGMA” cuz i hv faced so many problems for this. Thanks once again

  4. Shariff

    It was great to known about six sigma defination from your link..


    Six Sigma is very good concept and this knowledge can help company to reduce the tedious task while implementing any project.

  6. Alby

    I feel every should know about Six Sigma is very important and this link explains in simply words

  7. Aircav64

    In the US it’s call “Six Sigma” in Japan it’s called Kaizen or 5 S. I have worked with kaizen and the 5 S since 1993 and with all due repect, I will use these over Six Sigma. (maybe that’s why I keep getting told I’m over qualified) Look at the last sentence. This isn’t process is not taught/instilled with Six Sigma.

    5S is the name of a workplace organization methodology that uses a list of five Japanese words which are seiri, seiton, seiso, seiketsu and shitsuke. Transliterated or translated into English, they all start with the letter “S”. The list describes how items are stored and how the new order is maintained. The decision-making process usually comes from a dialogue about standardization which builds a clear understanding among employees of how work should be done. It also instills ownership of the process in each employee.

  8. David Mundy

    I worked under 6-sigma at AT&T. I found it to be an in-humane system that SCRUTINIZES employees way more than what is reasonable. This system treats humans like MACHINES. It puts a computer in command of the person as judge over every move you make. This is like being MICROSCOPED from 50 different parameters… then the boss starts hammering everyone for better efficiency, or accuracy or percent this percent-that. In a highly technical job it is IMPOSSIBLE to attain all the unreasonable goals they push for. It is a RECIPE for someone to go postal… was my experience. I finally had to quit the $32.00 dollar/hr job and go somewhere else that treats me like a human being… for $10.00 per hour! My family is really suffering now. I lost my retirement plans and I am 55 years old! Computers should not be judges of human productivity. Maybe AT&T implemented it wrong or something… I just cant believe all the people commenting on this page sounding like six-sigma is some kind of wonderful thing!!! what is wrong with you people?



  10. Troy Cole

    The standard practice of turning numbers of efficiencies with the way the human brain thinks is all in retraining our thought process and our view of what can be humanly achievable, it can be shown to employees on a chalk board daily and that process alone will increase productivity along with ownership from employees.

  11. Welingkar

    David Mundy’s response (08 February 2011 02:50) stemming from his plight is understandable and possibly something that all ‘scientific’ management exponents must take into account when using these techniques.

    These tools should not become the means for removing people from the job but used to see how human-machine-process interactions can be smoothened to achieve objectives. Unfortunately it is not just the consultants but even short-sighted managements, who are responsible for this mess.

  12. Jim Baker

    I am a general proponent of efficiency in manufacturing cycles and the use of six sigma techniques. However, in many industries I say a push for the use of six sigma when the number of products produced is one or two. What on earth is the six sigma on a sample of one? Using techniques to improve the production of an item is the normal work of engineers of all disciplines. I would prefer that we all work towards that goal without increasing compartmentalization of the work.

  13. Dinesh

    Very nicely explained Six Sigma.

  14. amin

    I am a general proponent of efficiency in manufacturing cycles and the use of six sigma techniques. However, in many industries I say a push for the use of six sigma when the number of products produced is one or two.

  15. Andy Mottershead

    Just started to Study Six Sigma for my MBA, thanks for all the tips and info on this site…..

  16. Kevin Clay

    Very well written and concise article. I especially like the paragraph about return on investment from a black belt. I am going to point my Belt students towards this page as a quick reference to the definition of Six Sigma. I look forward to reading more articles.


    Hi all,

    Six sigma is good to adopt in a manufacturing company only when each and every body understands the concept including the higher management staffs. Must be willing to collaborate and work as a team towards it.

    Definitely there are benefits in doing it.

    But must not replace people because of that.


  18. Joji Tom Mundakel

    The article sounds good. The six sigma is to industry what probably OODA(Observe Orient Decide Act) loop is to the military. The basic principles remain the same most of the time. Its just the jargon that changes. People nowadays like to be esoteric and throw high sounding jargon. I think the best thing is the KISS principle(another jargon) Keep It Simple and Stupid. We somehow seem to be in a continuous process of making life more complicated for ourselves.
    The six sigma can generate more money for the company . But does that serve any purpose to people in the company. And at what cost?

  19. Santhosh Kumar S

    Helpful for a beginner as well as a veteran.

  20. Ben Ace

    An Excellente point to improve production and focus on Management Operation based on the objectives and goals for any company apply it’s rule and it company purpose: the Six Sigma (define, measure, analyze, improve, control). Mr.Ben Ace-MBA. San Juan, Puerto Rico.

  21. Dave on a Rave

    Six Sigma is just a tool to be used to help a company produce higher quality products or services at lower costs in order to be competitive. Like any tool, if it is used without regard to the human aspects of the workplace, it can have an overall detremental effect and will not likely be sustainable. I’ve seen it executed well and also poorly. In regards to Mr. Munday’s post above, I would argue that it was not Six Sigma nor was it “computers” that caused the problem, but management that executed a program without fully understanding how to do so while maintaining employee dignity, value and trust. That is indeed unfortunate for all involved.

  22. Glenn Paul Limaco

    this is what i needed to learn… i have been reading a lot about this and its a field that is very much interesting that can make your brain think endless possibilities…

  23. Menno

    “So my mom can understand it” :-) I love it. Oh, and you delivered too. Excellent and concise description of Lean Six Sigma.

  24. Feroz Inamdar

    Good introduction into the basics of Six Sigma

  25. Dave McFarland

    probably need a little QC on the Cyger Murrow interview – someone needs to check Rick Murrow’s comments: near the 42 second mark: he says to make the customers more competitive, it is to make the businesses more competitive.

  26. Anonymous

    It seems some people really like sigmasix. But reading the negative comments on this made me cringe. In the stone age I worked in aerospace info tech. Upon occasion I worked on a quality improvements program. I have never heard of sixsigma. But I know that people are not machines. The description calls it a measure of quality that strives for near perfection.

    My first thought was, “Humans cannot achieve near perfection easily. That sounds stressful.” Then I wondered, “near perfection at what? Who is tasked with this near perfecting? Who is measuring and ensuring things are nearly perfect?” Perfection is an interesting concept. Is this perfection on a micro level? Or are there sweeping standards of perfection for all?

    Someone was talking about how hard it is to work in Info Tech under this system. I believe it. The workflow in certain types of information technology may not be a constant. Your role may be to produce like mad for a while, then hand off your product to another group. Then you are stuck waiting for some other group to finish their part before you get the project back in your lap again. In other words. It’s not that you work every minute. It’s that you are a specialist who does quality work when it is needed. And sometimes you try to look busy while waiting.

  27. Frazer Rendell

    A good insight. It seems like this will be perfect in a manufacturing environment where everything is controllable, such as make a bottle of coke. In a service environment which is full of human interaction it might need something else which encourages positive energy from the individual to achieve the best results.

  28. Theresa M. Mostasisa

    This was helpful.


    This why companies in the west and East are doing great while Kenyan companies still lag behind under traditional management processes.I tried to introduce 6 sigma somewhere but unfortunately my boss was semi illiterate and frustrated this great idea from great minds.6 sigma is the way to go

  30. Gary

    It replaces intelligence and decision making with mindless calculation.
    Great if you have lots of lowly paid, not so bright people involved.
    If you are struggling with overheads though, it requires you to do way more work than you would with a well thought out targeted approach.

    No-one would be doing it if the large USA customers weren’t forcing people into it.
    They like it for use in developing companies where labour overheads are cheap, and they don’t care if they put manufacturers out of business in other parts of the world.

    I’m not saying don’t utilise mistake proof methods, but when its overdone like the car companies want it gets crazy.
    ie a dob of grease for lubrication.
    Car company will want to apply a tolerance , so it becomes 5 grams ±2. Then the system capability has to be evaluated. Then the measurement system needs to be evaluated. ALL IT NEEDS IS A DOB OF GREASE.

  31. Rajashekhar.Patil

    Very good article. We have got lot of inputs from this article. We are also planning to do such methodologies in avoiding cost,defects and mistakes for our company products. Well, this was a nice part in doing so..

  32. Vinod Bhardwaj

    After you have exhausted with the improvements done using seven basic tools and have a good maturity of control charts, you should go for six sigma approach. Over 80 percentage of problems can be solved by basic seven tools using PDCA approach.

  33. mrsafetyman

    six sigma has flaws. No environmental or safety aspects are involved. It may provde verification but it forgets to Validate after verfiication is complete. There are many flaws and just another system someone decided to name six sigma and make huge bucks. Business like steelmaking always provided a quality product years ago before six sigma even presented itself. Everyone is looking for a buzz word process instead of good old hard work determination and documentaeion within each process. Where is the safety work process, the environmental process> all important in the manufacturing process. What else bothers me is the term manufacturing. So does assembly consider itself a manufacturing process or manufactruing facility? The facility assembles it doesnt manufacture. its part of the process. Always bothered me when companies think they are manufacturing when in fact they are vent for the day.

  34. San

    I don’t understand the reasoning behind so many comments that support this Six Sigma.. It has an attractive name – and that’s all about it.. As many pointed out, it is meaningless… Just a label for everything that is common sense.. Use your brain guys. I believe common sense and right brains can replace such inhuman good for nothing concepts like six sigma.. Enough is enough burning time and money for practically no gain.. Get back to real work and throw all these junk out of the window.

  35. San

    @Vinod Bhardwaj

    Wrong. those tools cannot solve the problem… 80% ? please stop this 80-20 useless philosophies… Probably you are working as a consultant or a so called “quality” manager. Are you not guilty of wasting the company’s time and money in pushing your useless propaganda ?

  36. Kimmy Burgess

    An extremely sensible, to the point explanation of the concept of Six Sigma to a layman. This helps to introduce and explain the concept to him and lets him understand what he can expect from Six Sigma. It would help a great deal if these articles could be industry specific other than for manufacturing companies. The common mis conception is that six sigma is applicable only to manufacturing companies.

  37. Kimmy Burgess

    It would help a great deal if these articles could be industry specific other than for manufacturing companies. The common mis conception is that six sigma is applicable only to manufacturing companies.

  38. Deepak Panda

    The term “Six Sigma” refers to the capability of processes to produce output within specifications with high degree of precision. In particular, processes that operate with six sigma quality produce at defect levels below 3.4 defects per million opportunities (DPMO). Six Sigma ’ inherent goal is to improve all processes to that level of quality or better.

    Six Sigma is a set of tools used for making business decisions originally developed by Motorola to systematically improve processes by eliminating defects. A defect is defined as nonconformity of a product or service to its specifications. While the particulars of the methodology were originally formulated by Bill Smith at Motorola in 1986, Six Sigma is heavily inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects.

  39. Sigma King

    really good stuff, I never knew six sigma was so important

  40. Engineer SAMIR IBRAHIM

    Thank you for giving me the meaning of this word ”SIX SIGMA” I have faced so many problems for this. Thanks once again I am in a process to explane the use of SIX SIGMA to my coleegs.

  41. Hillary Kivadze

    I use six sigma as atool to plan,organize,monitor and implement my projects which are so successful. So 6-sigma is aperfect tool in managerial field.

  42. Frank Leach

    Having companies strive for perfection could be the death kneel for new technology innovations brought to the forefront by independent inventors. Working from the premise that inventions from independent inventors fail 99% of the time, then you would advise large companies to bar any new idea suggestions from all independent inventors. Who knows, the next break through technology could from that very source.

  43. Zack

    Lean is a great way to reduce costs and lead times. We introduced lean recently on one product. We started with 368 steps from start to finsih with a total product travel distance of 1.3 miles within the factory. We just completed our future state map and cut our steps down to 133 with a travel distance of 300 feet within the factory. So yeah Lean works and works good. Good luck on your project.

  44. San

    Six Sigma is absolutely theoritical… Organizations can very well do without it… It is a myth that it increased productivity – it does nothing that can materially increase productivity… Check where the author debunks this myth entirely…

  45. David

    really good stuff, I never knew six sigma was so important and how soon we can learn.

  46. Dasha Davidovich

    As an Electronic engineer and greenbelt, I find the math tools useful and attractive. However, the statement “the avererage salary for a Black Belt is $80,000 in the U.S.” instantly stomped out my enthusiasm for that goal; better spend my time improving EE skills!

  47. Joanne

    Thanks for sharing. It is very brief yet concise article regarding six sigma. I have only known this methodology through a client (a former engineer in GE). Six Sigma should be implemented if you want to grow big time.

  48. Bridget

    Article is a simplified definition of six sigma. Per the six sigma way, it states data to demonstrate results.
    I like the way the article outlines value$ to the individual green belt by mention of average salary in addition to bottom line savings to companies, specifically GE.
    When you become part of six sigma implementation you gain value. You facilitate the elimination of waste, standardize processes, realize how important is is to utilize untapped talent (rather than lose to another employer), and inspire the paradigm change required to affect the bottom line.
    Lean six sigma is a theology for business. People first need faith that it works. Once they’re convinced, they need repeat infusions and activities to sustain the belief that it is worth it. It is no simple and easy program to follow. It is an all in enthusiasm and commitment to engage top to bottom, peer to peer, mentor to mentored. I hear over and that sustain is the most difficult stage. If the foundation and process aren’t respected and followed from the start, that will undoubtedly plague the organization.
    I whole hearted.y believe in lean six sigma. I also know I need to use all the talents I have stashed away to infect my organization quickly and completely with six sigma.
    I would go on longer, but I am actually at a pit stop here looking for an assignment for a course. I wish I had the correct tools to simply complete my training efficiently. Frustrating. I won’t forget these feelings when it’s time to help operators learn and apply lean six sigma practice to their areas.
    Off I go to try and use incomplete accesses, poorly designed online classes and slow connections to learn and succeed in certification.


  49. Mitchell L Gold

    Is Lean Six Sigma considered leading edge these days? I am investigating one of the adherents to this progam and frankly it is a very dated concept in business evolution – IMHO

    I was knocked dumb by your fisherman story adaptation. certainly we have gone beyond that. and if you have not, maybe there is a reason.

    is your program intended to be an improvement on De Bono’s Six Hats Theory – or a new concept on its own.

  50. Tracee wilson

    Great information!!!

  51. James Grainger

    This is a very informative article. I have recently been struggling to figure out what Six Sigma is but this has helped me a lot!

  52. Alfred

    i worked with GE MONEY under this six sigma, unfortunately not many of the managers knew about it in detail, they reduced the tool to only productivity. my thoughts are six sigma is not about just lower cost and higher productivity of either services or goods, it’s about their quality ,and if implemented , a company should adopt it across the board , in employee performance and HR issues.This would ensure no nepotism or crap takes place , at the end of the day, six sigma can’t replace the human touch to a situation or the saying ” people work for people’ guess that philosphy should be better than six sigma

  53. Javier Garcon

    So far all the companies you have mentioned are down in stocks right now, meaning whatever six sigma did in the past is suffering. Just like the next President of the United States will inherit the last Presidents Legacy pretending it is his own and that he made it happen. It takes 4 to 10 years for whatever a person’s leadership creates to come to reality, that is after they have left the company or government. I do not believe six sigma works at all and all it does is put a band-aid on a very long problem. Becoming a computer machine is not an improvement.

  54. Srinivasa.K.N

    Good introduction thanks for that.

  55. Ephraim Makwatse

    Six Sigma emphasizes simple and yet reliable process/variation and products/services. Simplification of processes and variation makes life easier for business and its support agents while reliability of products and services is core to customer experience and satisfaction. Toyota has made it through application and practice of these programs.


    Very Informative!

  57. Manjunath Ramaswamy

    Very useful information I got to know something new, and learnt what is the meaning of six sigma.
    manjunath ramaswamy

  58. Muhammad Soban Badar

    I think its a good info at least who are opposing this six sigma knowledge they must understand that some thing is better than nothing.

  59. Rafael Sbeghen Senise

    Six Sigma is a set of practices originally developed by Motorola to systematically improve processes by eliminating defects. A defect is defined as nonconformity of a product or service to your specifications. Six Sigma is also defined as a management strategy to promote change in organizations, causing it to reach improvements in processes, products and services to customer satisfaction. Unlike other forms of management of productive or administrative processes Six Sigma’s priority is to obtain results in a planned and clear as much quality as mainly financial.

  60. Koushik

    Good introduction into the basics of Six Sigma.

    Definitely worth a read for beginners.

  61. Ebinu Denis

    Very brief to the point and very useful information especially to a person new to Six Sigma like me.

  62. Krishna Saurabh

    Thanks for briefing about the concept. However the six sigma being an ocean this article summaries about the whole topic.

  63. Alva

    Great Blog, Good explanation of six sigma.

  64. Lords

    Sometimes this six sigma business is not applicable if the person doing is not very very familiar with the product . All the person with this 6 sigma business got a theory and rushing to implement it in work force that caused a mayhem.

  65. Dr. N.R.U.K.Kartha

    Went through the audio of six sigma. Excellent presentation in very simple language, easily understood by beginners too.

    all the best

  66. Rohit Kumar

    Good information about six sigma.

  67. Regragui Maroua


    If I had to define Six sigma, I would say a tool instead of a methodology. I believe that Lean is more of a methodology. this is because while Lean is ongoing, I feel like Six sigma is a tool that does not have to be ongoing. What do you think?

    thank you in advance for your input.

  68. Kumar Gaurav

    Nice one ?

  69. BMGI India

    Six Sigma is an improvement methodology process outputs of identifying and removing the causes of defects. It is developed by Motorola and later popularized by GE aims at minimizing variability in manufacturing and business processes. Using the set of quality management methods It focuses on reducing process variation by using PDCA based approach DMAIC. It includes reduce pollution, reduces costs, increases customer satisfaction, and increase profits

  70. isaacakram

    I wish i have all the knowldge of the six sigma so that I can correct of all defects of the world.

  71. Mike Slater

    GE HAS always been a proponent of the Six Sigma. I wonder why GE stock has done so poorly in relation to the rest of the market and peers?

  72. Graham

    Once upon a time there were efficiency experts that did exactly the same thing and caused the same problems with employee’s. Now through the miracle of jargon we have Six Sigma. “A rose by any other name…”. If a decent project manager had been hired in the first place you wouldn’t need this specialist. BTW I can’t spell but I can use spell check with out “Six Sigma” training.

  73. 6 sigma rocks!

    6 Sigma is a tool. If not used correctly, it is as useful as tits on a boar. Would you use a adjustable wrench to hammer a nail? A hammer to tighten a bolt?

    Anyone that states that 6 Sigma is waste don’t understand how to use it properly.

    In manufacturing today, it’s all about time & money. To eliminate waste is the game. Continuous improvement…what’s wrong with that?

  74. Nick Johnson

    Great and informative article. Actually, I have read different things about Six Sigma but those are difficult to understand but this article is easy to understand. Thanks

  75. Rohit

    Very useful article of six sigma

  76. SeventhSigma

    This organization is a joke. I overheard someone using the “5 whys”. He ended up sounding like a condescending overbearing helicopter parent before he got the third one out. Six Sigma is snake oil. This is your true 50k ft level explanation.

  77. Jon

    Six sigma is just one of the tools of lean management.

  78. alex

    The six sigma approach is one of the best approaches that helps in elimintaing unnecessary expenses and streamlining operataions in a firm. it is the best tool that can be relied upon in promoting good customer relations since it is customer focused.

  79. Ron Davis

    Corporate nonsense and goobledygook! Companies use it to brow-beat and alienate their workforce. Used by people who have no leadership skills to demand excellence from coworkers and subordinates. Waste of time and money to organizations rather than empowering people to innovate and truly solve problems.

  80. Jacob Myth

    Thank you for this informative post

  81. Kalash

    “driving toward six standard deviations between the mean and the nearest specification limit” is what is written, but isn’t it 3 standard deviations between mean and limit? Or maybe 6 standard deviations between the upper and lower limits? Cause that is how it is written on the normal distribution map.

  82. Realtimedairy

    Thanks for shedding some light on this and making it clear that Six sigma basically refers to the strategies implemented with the aim of improving output quality. This is achieved by identifying sources of defects and minimizing variability in a business or manufacturing process.
    With such basics it shouldn’t be hard to dig deeper into the science behind the whole issue. Thanks.

  83. Kathy Castle

    Thank you for this useful post. Six Sigma DMAIC and DMADV concepts are very important concepts in quality management.

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