Talk:Six Sigma

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[edit] Terrible!

This entire article is written in incomprehensible corporate doublespeak. It needs a rewrite. Pw33n (talk) 06:01, 28 April 2008 (UTC)

Did you know that you can help improve the quality of the article tremendously simply by marking the parts that you feel need clarification with {{clarifyme}}? Note that it is vastly more helpful to mark individual sentences or sections than it is to tag the entire article with {{clarify}}. Please see Wikipedia:Please clarify for more details.
-- DanielPenfield (talk) 12:48, 28 April 2008 (UTC)
Agreed. By the nature of the beast, there will always be some "corporate doublespeak" in the article, as well as some statistical reasoning that will be above the head of the general reader. Having said that, I agree that the article can do with improving, so specific pointers to sections that are hard to understand or badly structured might be useful. Jayen466 01:31, 29 April 2008 (UTC)
One suggestion: Do we need the table on "Other Design for Six Sigma methodologies"? It's just a list right now, with a lot of words that aren't really saying very much and are likely to make the reader's eyes glaze over. Should we lose it? Jayen466 01:34, 29 April 2008 (UTC)
Yes. I must admit I sympathise with Pw33n - even the first sentence is so generalised (although entirely accurate) that it is not much help to the average punter. I think the article is being written by, and addressed to, practitioners (or worse) which is not what a general purpose wiki article should be. It is, to use an appropriate metaphor, as though the wiki article(s?) on prostitution were written by pimps and call girls, for pimps and call girls. Greg Locock (talk) 02:03, 29 April 2008 (UTC)
Okay, we can and should lose some of the corporate jargon and use more general language. Much of the article is also woefully unsourced ... Jayen466 00:15, 30 April 2008 (UTC)
Wikipedia:Make technical articles accessible encourages us to avoid "dumbing down the article". Furthermore, "just adding more words" and "just using different jargon" (e.g., "non-fulfilment" instead of "nonconformity") does not help anybody's understanding. Instead of flailing about, why don't we put more effort into understanding what drives these periodic reactions of disgust (i.e., the D, M, and A in DMAIC). Once we understand, then we can improve. Wikipedia has mechanisms that we can take advantage of: Wikipedia:Requests for comment, Wikipedia:Third opinion, and maybe others I don't know about.
Finally, it is clear that we're "editing' the article without having widely read up on the subject. Why not take some time to hit the local college library and dig up sources that are closer to the origin of Six Sigma--in my own effort, I find these are less subject to distortions from Chinese whispers or sales spin (though they are hardly free of that). Arguably this is the first step we ought to take.
-- DanielPenfield (talk) 13:50, 30 April 2008 (UTC)
I agree that we need to access sources, and I'll have a look what I can dig up in google scholar and the questia.com library. As for my recent attempts to clean up the language and the "dumbing down" you fear might occur, I'd like to hear views from other editors. I've been involved in the creation of training materials on these topics for 20 years; in my experience, expressions like "process", "nonconformity" and "reducing variation" are not readily understood by the general public. That is why each foundation course begins with a definition of these terms. So I would like the intro at least to use more general language that does not immediately put the general reader off. Sentences like "Continuous efforts to reduce variation in process outputs is key to business success" are pure jargon (apart from being shoddy grammar) – standard in companies that apply these methods, but not very good style for an encyclopedia. I think this is what bugs readers most. For a general overview – which is all we can aspire to here for now – the language should be more accessible. But I am perfectly happy to be guided by consensus. Jayen466 15:29, 30 April 2008 (UTC)
  • "apart from being shoddy grammar"
Feel free to correct subject-predicate agreement issues independently of stylistic edits, then.
  • "That is why each foundation course begins with a definition of these terms. So I would like the intro at least to use more general language that does not immediately put the general reader off."
It sounds like you haven't read Wikipedia:Make technical articles accessible beyond the first paragraph. In particular, Wikipedia:Make_technical_articles_accessible#"Introduction to..." articles sounds like a better solution than what you've set out to do on your own.
  • "I've been involved in the creation of training materials on these topics for 20 years"
Based on my reading of Six_Sigma#Origin_and_meaning_of_the_term_.22six_sigma_process.22, I have to infer that you're training children, as, quite frankly, that's the level of diction that you seem to prefer. I cannot believe that the average Wikipedia reader needs to have the term "sigma" explained to him. (And if he does need explanation, that he's incapable of clicking on the hyperlink to find out for himself.) I also cannot believe that the use of smarmy phrases like "often used by quality professionals" is encyclopedic. It really sounds to me like you believe your audience is uncapable of understanding anything but the most basic, watered-down content and is incapable of cross-referencing terms that they find novel as they read the article. I believe you are wrong: Your audience is much more intelligent than you believe.
  • "Sentences like "Continuous efforts to reduce variation in process outputs is key to business success" are pure jargon"
As User talk:Greglocock has already pointed out it is very, very difficult to come up with content that is equivalent, yet could be readily understood by someone with no exposure to this area of knowledge. You were unable to do it yourself. I think most people would agree, however, that it is an improvement over where we were last year. Additionally, had you actually read "The Nature of Six Sigma Quality" (the historically important reference that you deleted and re-added a few months back), you'd have to admit that bullet point an accurate summary of what Mikel Harry wrote in its introduction ("Why Variation Is the Enemy").
In summary, here's what I understand to be our points of contention:
  1. You believe the audience for this article is much less intelligent than I do.
  2. You believe (or believed) that you have enough knowledge to edit the article without significant background reading.
  3. You believe that there is only one course of action: Hack up the article in isolation, when there are other avenues (notably Wikipedia:Make_technical_articles_accessible#"Introduction to..." articles and Wikipedia:Requests for comment) which I argue would produce better results for everyone.
-- DanielPenfield (talk) 16:30, 30 April 2008 (UTC)
It seems to me you're not listening to the Voice of the Customer. You wrote "We really don't understand what it is about Six Sigma that so bothers people that they express their disgust on Talk:Six Sigma—they are uniformly unable to articulate anything actionable, despite repeated encouragement." That's not entirely true – what the people above have said is that the article is "incomprehensible corporate doublespeak", that it feels like it is "written by, and addressed to, practitioners", and that it is full of "quasi-meaningless management consultancy jargon and fashionable corporate buzzwords". Can't you see what they mean? Jayen466 16:41, 30 April 2008 (UTC)
No, I can't, that's why I asked for {{clarifyme}}, repeatedly (User talk:LaylahM‎, User talk:Statman45‎, User talk:Pw33n). You presume to know what they're talking about, yet your edits lead me to believe otherwise—you rely on simple expansions of the obvious ("achieve greater uniformity (or reduce variation)" instead of "reduce variation", "the non-fulfilment of any aspect" instead of "nonconformity", etc) or statements of no value at all ("A brief outline of the statistical background follows below." in a section already entitled "Origin and meaning of the term"). I'll ask again, rhetorically: Did you really improve the article? Did you make it more clear? Or did you just switch a few words around and find more complex ways of describing things? And did you delete genuinely useful stuff like the diagram you deleted last time because you're not familiar with the material?
-- DanielPenfield (talk) 17:16, 30 April 2008 (UTC)
Also, people freely voiced their disgust before the addition of the bulleted items you're focusing on, so there's got to be something else (or in addition) that really bothers them. -- DanielPenfield (talk) 17:52, 30 April 2008 (UTC)

(outdent) Like I said above, my experience is that "reduce variation" means little to the general reader, whereas "achieving greater uniformity" is a useful paraphrase in non-statistical language that anyone can understand. That is exactly what WP:Make technical articles accessible is talking about. Let's look at what else it says there, apart from "Don't dumb down":

  • Put the most accessible parts of the article up front. It's perfectly fine for later sections to be highly technical, if necessary. Those who are not interested in details will simply stop reading at some point, which is why the material they are interested in needs to come first. Linked sections of the article should ideally start out at about the same technical level, so that if the first, accessible paragraph of an article links to a section in the middle of the article, the linked section should also start out accessible.
  • Add a concrete example. Many technical articles are inaccessible (and more confusing even to expert readers) only because they are abstract. Examples might exist in other language wikis, such as German/Italian wikipedias, which have statistical examples. Use Google, Yahoo! or Systran translation, etc. to help convert.
  • Use jargon and acronyms judiciously. In addition to explaining jargon and expanding acronyms at first use, you might consider using them sparingly thereafter, or not at all. Especially if there are many new terms being introduced all at once, substituting a more familiar English word might help reduce confusion (as long as accuracy is not sacrificed).
  • Use language similar to what you would use in a conversation. Many people use more technical language when writing articles and speaking at conferences, but try to use more understandable prose in conversation. [1]
  • Use analogies to describe a subject in everyday terms. The best analogies can make all the difference between incomprehension and full understanding.

I think the article could benefit a lot from implementing these recommendations, plus solid sourcing. Btw, as per WP:LEDE we shouldn't be having those bullet points in the lede. And if these bullets are sourced to Harry, then it would be advantageous to add a reference that makes that clear. Cheers, Jayen466 18:18, 30 April 2008 (UTC)

Plus, I really think the "alphabet soup" list under "Other Design for Six Sigma methodologies" should go, or should at least go to the end of the article. Too much detail too early in the article, and practically useless without explaining what these companies understand by these terms. Jayen466 18:22, 30 April 2008 (UTC)

I still don't understand precisely to what you're objecting. Perhaps you could humor me by starting with the lede alone and going line by line:
Sentence User talk:Jayen466 opinion User talk:DanielPenfield opinion
Six Sigma is a set of practices originally developed by Motorola to systematically improve processes by eliminating defects. "Process" on its own is unclear. That is why books on Six Sigma first explain what is meant by process. Accurate and clear
Buzzword free, with the exception of the article title
A defect is defined as nonconformity of a product or service to its specifications. "Nonconformity to specifications" is a jargon expression here, we could say something like "failure to meet all the requirements defined in its specification". Btw, feel free to come up with something better! Required to explain preceding sentence
Buzzword free
While the particulars of the methodology were originally formulated by Bill Smith at Motorola in 1986, Six Sigma was heavily inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects. Fine This sentence is necessary to give one an idea as to what Six Sigma is by relating it to past efforts in the same arena--if Joseph M. Juran can't see the difference between Six Sigma and the Statistical Quality Control he used for seven decades (see [1]), then really, there probably is no material difference.
Buzzword free, with the exception of the necessary evil of the methodology names and the article title
Like its predecessors, Six Sigma asserts the following: What could be made clearer is the claimed effect on a company's bottom-line profitability, by reducing the cost of bad quality. That is a major aspect of how Six Sigma is sold to management. Another aspect that could be made clearer is the data-based approach. Yet another is that it is supposed to be a complete management system, changing fundamentally the way a company is managed. That includes the team-based cross-functional approach, and the role of Black Belts. (Also in this vein, see the more recent Mikel Harry quote below, under "Suggested sources".) Six Sigma's dirty little secret is that one never seems to be able to find anyone to give a clear overview of what exactly it is and how it differs from its predecessors. I've been looking for two years and haven't found anything that ever comes close. This is a "best effort" attempt to summarize the core principles, which, by the way aren't really that different that SQC, ZeroDefects, TQM, etc.
Buzzword free, with the exception of the article title
Continuous efforts to reduce variation in process outputs are key to business success The whole sentence is jargon and can be put in more general language. You cannot assume that everyone checking into this article is familiar with the concept of variation as measured by standard deviation or variance. As User:Greglocock noted, this is "entirely accurate". It's necessary to point out that variation is the thing to be controlled as the intuitive "no defects" = OK is the thing Deming, Taguchi, Juran, Crosby, etc. criticise as misguided.
As near as I can tell, you object to one or more of the following as "fashionable corporate buzzwords": "Continuous efforts", "process outputs", and/or "business success".
Manufacturing and business processes can be measured, analyzed, improved and controlled Shorthand jargon. A process can't be measured. You measure parameters of the process, or product characteristics. You then analyze the data collected. A plain English restatement of DMAIC
Buzzword free
Succeeding at achieving sustained quality improvement requires commitment from the entire organization, particularly from top-level management Fine. Repeated to death in pretty much anything one reads about Six Sigma (and SQC, ZeroDefects, TQM, etc. for that matter), so repeated to death here.
Buzzword free, with the possible exception of "quality improvement"
The term "Six Sigma" refers to the ability of highly capable processes to produce output within specification. "Capable process" is not part of the general vocabulary. It means little to someone who has never heard of a process capability study. Also tautological; capability is defined as the ability of a process to consistently produce output within spec. Summary of "Origin and meaning of the term "six sigma process"" section with wikilinks to technical terms.
Buzzword free, technical terms wikilinked
In particular, processes that operate with six sigma quality produce at defect levels below 3.4 defects per (one) million opportunities (DPMO). "processes that operate with six sigma quality" -- please, what does this tell a person who doesn't know this already? Perhaps the only thing unique to Six Sigma is specifying the process capability "goal"—this is of course criticized in the "Based on arbitrary standards" section
Buzzword free with the exception of "six sigma quality" which this sentence actually defines, technical terms wikilinked
Six Sigma's implicit goal is to improve all processes to that level of quality or better. Okay, sort of. ;-) Required to emphasize preceding sentence and provide motivation for the Six Sigma methodology
Buzzword free, with the exception of the article title
-- DanielPenfield (talk) 21:20, 30 April 2008 (UTC)

Let's first of all have a look at WP:LEDE. The lede is supposed to be a summary of the article as a whole. It is not supposed to introduce information that is only found in the lede and occurs nowhere in the remainder of the article. Jayen466 22:39, 30 April 2008 (UTC)

Re the last para of the lede, "In addition to Motorola, companies that adopted Six Sigma methodologies early on and continue to practice them today include Honeywell International (previously known as Allied Signal) and General Electric (introduced by Jack Welch).". This makes it sound like there are a half dozen companies out there doing this. Compare this against the following: In the late 1990s, about two-thirds of the Fortune 500 organizations had begun Six Sigma initiatives aimed at reducing costs and improving quality. (Juran Institute's Six SIGMA Breakthrough and Beyond, p. 6.) Jayen466 23:57, 30 April 2008 (UTC)


User talk:Jayen466 statement User talk:DanielPenfield response
"Process" on its own is unclear. That is why books on Six Sigma first explain what is meant by process. It is now wikilinked so that those unfamiliar with the term can easily discover what it means. Wikilinking eliminates the need to duplicate its definition in article after article after article that refers to it. You are the only editor that I've encountered in my three years of active editing who has problems grasping this concept.
"Nonconformity to specifications" is a jargon expression here, we could say something like "failure to meet all the requirements defined in its specification". Btw, feel free to come up with something better! If you had actually read up on the subject, you'd know that this is the terminology that quality practitioners, statisticians, and managers use. To invent some new term does nobody any good. Furthermore, I believe most readers are intelligent enough to understand what it means.
What could be made clearer is the claimed effect on a company's bottom-line profitability, by reducing the cost of bad quality. That is a major aspect of how Six Sigma is sold to management. Another aspect that could be made clearer is the data-based approach. Yet another is that it is supposed to be a complete management system, changing fundamentally the way a company is managed. That includes the team-based cross-functional approach, and the role of Black Belts. (Also in this vein, see the more recent Mikel Harry quote below, under "Suggested sources".) If you had actually read up on the subject, you'd realize that SQC, ZeroDefects, TQM, etc., etc., etc. all make these claims. The key is that each successive "methodology" has to portray its predecessors as less comprehensive, not focused on the bottom line, making superficial changes versus the "all encompassing", fundamentally changing, bottom-line focus of the "new" methodology, which invariably incorporates the old methodologies with a new sales spin.
In other words, Six Sigma is pretty much like its predecessors with some new terminology, hence "Like its predecessors, Six Sigma asserts the following"
The fact that you alone refer to it as the "cost of bad quality" when the rest of the world knows it to be the Cost of poor quality is yet another red flag that you simply have not done enough reading to comment intelligently on anything related to quality.
The whole sentence is jargon and can be put in more general language. You cannot assume that everyone checking into this article is familiar with the concept of variation as measured by standard deviation or variance. Put your money where your mouth is and offer a counterproposal. Additionally, I cannot believe that readers are as poorly informed as you claim. We are not writing an encyclopedia for high-school dropouts here.
Shorthand jargon. A process can't be measured. You measure parameters of the process, or product characteristics. You then analyze the data collected. Then change the wording to fit your whim: Use "aspects of manufacturing and business processes" or some equivalent.
"Capable process" is not part of the general vocabulary. It means little to someone who has never heard of a process capability study. Also tautological; capability is defined as the ability of a process to consistently produce output within spec. It is wikilinked so that those unfamiliar with the term can easily discover what it means. Wikilinking eliminates the need to duplicate its definition in article after article after article that refers to it. You are the only editor that I've encountered in my three years of active editing who has problems grasping this concept.
"processes that operate with six sigma quality" -- please, what does this tell a person who doesn't know this already? Can you read? It tells them that six sigma quality == very low defect levels and gives them the magnitude: 3.4 defects per (one) million opportunities (DPMO)
You are the only editor that I've encountered in my three years of active editing who has problems grasping this concept. Then re-read the comments from other editors above. You are ignoring the fact that editors regularly comment on this talk page that the article is very poorly written. Someone commented three days ago that it was written in "incomprehensible corporate doublespeak". Another said, last October, about essentially the same article that we have now, "Ive read this page several times and still have no idea what 'six sigma' is meant to be; the article is just a string of quasi-meaningless management consultancy jargon and fashionable corporate buzzwords. Could someone rewrite the article with all the bullshit removed, in a format suitable for wikipedia rather than an inane powerpoint presentation."
If you had actually read up on the subject, you'd know that this is the terminology that quality practitioners, statisticians, and managers use. To invent some new term does nobody any good. Furthermore, I believe most readers are intelligent enough to understand what it means. Again, this is precisely what an editor criticised a couple of days ago, citing this very sentence we are discussing here: "I think the article is being written by, and addressed to, practitioners (or worse) which is not what a general purpose wiki article should be. It is, to use an appropriate metaphor, as though the wiki article(s?) on prostitution were written by pimps and call girls, for pimps and call girls." I think there is ample evidence that editors have characterised the article as not increasing their understanding. It is ludicrous to argue otherwise.
In addition, the content in the bullet points is unsourced. Did you not say it was closely based on Harry's book? Could you provide a title, page number etc., so we can add a cite? And it needs to be moved from the lede to the article proper, as per WP:LEDE. Jayen466 09:33, 1 May 2008 (UTC)
If you had actually read up on the subject, you'd realize that SQC, ZeroDefects, TQM, etc., etc., etc. all make these claims. The key is that each successive "methodology" has to portray its predecessors as less comprehensive ..., not focused on the bottom line, making superficial changes versus the "all encompassing", fundamentally changing, bottom-line focus of the "new" methodology, which invariably incorporates the old methodologies with a new sales spin. Well, to make this NPOV, I'd suggest we first say what the claims of the Six Sigma folks are. Then there can be a discussion of these claims, using comments like the one sourced to Juran, with attribution and a reference.
We are not writing an encyclopedia for high-school dropouts here. Please show me the policy or guideline that says that. As far as I am aware, we are writing an encyclopedia for use by the general population, not just that section of it that has been educated beyond a certain level. Jayen466 11:06, 1 May 2008 (UTC)

[edit] Suggested sources

(ec) We need to base the article on sources. The following books provide well-written, relatively jargon-free explanations of what Six Sigma is. Please state whether you feel these are acceptable (and feel free to add more). Jayen466 16:32, 30 April 2008 (UTC)

  • Pyzdek, The Six Sigma Handbook, McGraw-Hill Professional: [2] -- this has a useful intro to Six Sigma
  • Tennant, Six Sigma: SPC and TQM in Manufacturing and Services, Gower Publishing, Ltd.: [3]
I believe Pyzdek to be a serial spammer, based on http://en.wikipedia.org/w/index.php?title=Talk:Six_Sigma&diff=next&oldid=95763527 and the frequency at which his books are anonymously added as "references" (http://www.google.com/search?hl=en&q=pyzdek+site%3Aen.wikipedia.org). I also took a look at one of his books and wasn't particularly impressed.
I believe the best references will be ones written by Motorola people before 1995, as these are closest to the origin of Six Sigma before it gained its current notoriety and everybody put his own spin on it. In particular:
  • The Harry brochure ("The Nature of six sigma quality") was required reading in a recent certification program I attended (Ph.D. statisticians with decades in the practice, not consultants of dubious origin).
  • Articles from ASQ publications (like Quality Progress) that introduced the topic in the mid- to late- 1990s
  • Books by notable statisticians (e.g.,Hoerl, Snee, Marquardt, etc.)
  • Books by notable quality experts or at least with their imprimatur (e.g., Juran, Feigenbaum)
-- DanielPenfield (talk) 16:48, 30 April 2008 (UTC)
The Pyzdek book is well cited according to google scholar ([4]) and from a reputable publisher. Let's agree that we need both those original sources and more recent ones charting the growth of the methodology. How about placing a Request for Comment? Jayen466 18:03, 30 April 2008 (UTC)
As I understand it, editors accepting our Wikipedia:Requests for comment would likely balk at us asking which sources are "best"--they're pretty much there to review articles, templates, categories, or users.
How about this suggestion?:
You, for your own benefit, find a pre-1996 Six Sigma book that you could read or at least browse locally (e.g., using http://www.worldcat.org/search?q=ti%3Asix+sigma&fq=yr%3A..1996+%3E&qt=advanced) and compare it to Pyzdek.
Find Quality Progress back issues at your local library (e.g., via http://www.worldcat.org/search?q=quality+progress&qt=results_page) and read at least the first first article with "Six Sigma" in the title, from June 1993, p 37 "Six Sigma Quality Programs" and compare it to Pyzdek.
You'll be able to verify for yourself what I've been emphatically stating and, more importantly, you'll have broadened your horizons enough where you'd be on a better footing to add or change content.
-- DanielPenfield (talk) 18:51, 30 April 2008 (UTC)
I've got quite a few old Quality Progress copies from the nineties on my bookshelf. ;-) I do not understand why you would want to somehow restrict this article to Six Sigma as it was in 1993. It's like writing an article about communism and insisting that Lenin, Stalin, Tito etc. have nothing to do with it. By all means, let's bring material from these early sources into a history section, but the understanding and relevance of Six Sigma today is not adequately covered that way. And I really don't see that this article is so brilliant as it stands at the moment. Jayen466 22:37, 30 April 2008 (UTC)
Here is a more recent quote from Mikel Harry re the difference between TQM and Six Sigma:
MIKEL HARRY: I think Six Sigma is now squarely focused on quality of business, where TQM is concerned with the business of quality. That is, when you adopt TQM, you become involved in the business of doing quality, and when you adopt Six Sigma, you're concerned about the quality of business. In a nutshell, TQM is a defect-focused quality improvement initiative, whereas Six Sigma is an economics-based strategic business management system. Didn't start off that way, but it has evolved that way. Book Title: Rath & Strong's Six Sigma Leadership Handbook. Contributors: Thomas Bertels - editor. Publisher: John Wiley & Sons. Place of Publication: Hoboken, NJ. Publication Year: 2003. Page Number: 5. Jayen466 23:47, 30 April 2008 (UTC)
"I think Six Sigma is now squarely focused on quality of business, where TQM is concerned with the business of quality." Now, I think that is exactly the sort of smart ass comment that typifies the problem with this article. Yes, it does sort of make sense,and is moderately amusing. But it is profoundly unhelpful in an introductory article for 6S. I would vote very strongly to keep the alpabetti spaghetti such as alternatives to DMAIC out, they are just astroturfing by pimps, not essential to a basic understanding of the subject. I am a bit surprised about the dirty little secret comment, I'd have said the differences were obvious - 6S is marketed to senior management first, and presented in terms they can understand ($). It coopts the technical, statistical and problem solving methodologies built up over the last century and presents them in a coherent framework. Greg Locock (talk) 04:03, 1 May 2008 (UTC)

Another source you might like is the "Juran Institute's Six SIGMA Breakthrough and Beyond". Jayen466 23:39, 30 April 2008 (UTC)

"I do not understand why you would want to somehow restrict this article to Six Sigma as it was in 1993."
I never said this. What I said was "I find [sources closer to the origin] are less subject to distortions from Chinese whispers or sales spin." I never "restricted" anything—that is completely your invention.
"It's like writing an article about communism and insisting that Lenin, Stalin, Tito etc. have nothing to do with it."
Conversely, the analog of your approach would be to just pick just one and only one source from the works of Fidel Castro, Kim Il-sung, or Ho Chi Minh and completely ignore Marx, Engels, Plekhanov, Lenin, and Trotsky.
You also conveniently ignored my final two recommendations, which tend to be less prone to B.S.:
  • Books by notable statisticians (e.g.,Hoerl, Snee, Marquardt, etc.) NO DATE SPECIFIED
  • Books by notable quality experts or at least with their imprimatur (e.g., Juran, Feigenbaum) NO DATE SPECIFIED
"And I really don't see that this article is so brilliant as it stands at the moment."
You're confounding the article's need for improvement with your need to improve your understanding of the subject matter: We would be better off if both happened.
"Another source you might like is"
Just do us both a favor: Read (or browse) multiple sources from different timeframes. It would also be beneficial if you read something on statistical process control so that you can start to understand that Juran was right: Six Sigma is pretty much a case of "what's old is new again".
"In a nutshell, TQM is a defect-focused quality improvement initiative, whereas Six Sigma is an economics-based strategic business management system."
This is 100% sales pitch and a graphic illustration as to why one really ought to revisit the older sources which were written before Six Sigma became a road to big $$$$.
I am not interested in your personal opinion on Six Sigma. I am interested in making this an article that is easy to understand, explains the topic, and is based on reliable sources. This should include the notable criticism that Six Sigma appears to have spawned a lucrative cottage industry for consultants, trainers etc. Statements to that effect are available in the literature and can be sourced. Jayen466 09:54, 1 May 2008 (UTC)
Let me add that I've got nothing against Hoerl and Snee. I'd be delighted if you added well-sourced, readable content to the article! But I think you are prejudiced with regard to Pyzdek. As fas as I can see in google scholar, Pyzdek's tome is more widely cited than either Hoerl or Snee. Google scholar is commonly used in Wikipedia as a criterion for measuring the influence and notability of a writer. And which book(s) by Marquardt did you mean? Jayen466 12:05, 1 May 2008 (UTC)

Here is another well-cited book on Six Sigma that would make an excellent source: Implementing Six Sigma: Smarter Solutions Using Statistical Methods by Forrest W. Breyfogle, III

Obviously, "Six Sigma: the breakthrough management strategy revolutionizing the world's top corporations" by MJ Harry, R Schroeder belongs in the list as well, along with Harry's earlier publications. Jayen466 12:19, 1 May 2008 (UTC)

[edit] Differences between Six Sigma and earlier quality improvement initiatives

Here is a paper entitled "Pros and cons of Six Sigma: an academic perspective" that outlines some purported differences between Six Sigma and earlier quality improvement initiatives. Also has a useful overview of literature. (Originally published in TQM Magazine, I believe.) Jayen466 13:07, 1 May 2008 (UTC)

[edit] Statistics and robustness

The core of the Six Sigma methodology is a data-driven, systematic approach to problem solving, with a focus on customer impact. Statistical tools and analysis are often useful in the process. However, it is a mistake to view the core of the Six Sigma methodology as statistics; an acceptable Six Sigma project can be started with only rudimentary statistical tools.

Still, some professional statisticians criticize Six Sigma because practitioners have highly varied levels of understanding of the statistics involved.

Six Sigma as a problem-solving approach has traditionally been used in fields such as business, engineering, and production processes.

Why does this section have the heading "Statistics and Robustness"? We don't explain what robustness is, in fact, the word does not recur in the entire section. It's just a gratuitous buzzword. Moreover, the entire section is unsourced WP:OR. Jayen466 23:19, 30 April 2008 (UTC)

It's something somebody wrote years ago and I would not be sad to see it go, though I don't presume to understand what the original author was trying to convey. BTW, if you actually read anything at all on the subject, you'd know that robustness is a technical term (designing a product so that it performs well no matter what the inputs are, the goal of Taguchi methods, and DFSS). Since you can't be bothered to read anything on process or product improvement you will naturally believe that it is a "gratuitous buzzword". -- DanielPenfield (talk) 00:07, 1 May 2008 (UTC)
Daniel, I know very well what Robustness is, who Taguchi is, what a signal-to-noise ratio is, what Parameter Design is, what an orthogonal array is, what a screening experiment is, what a response-surface design is, etc. But that does not mean we can gratuitously drop in the word robustness just because it sounds cool! Jayen466 00:11, 1 May 2008 (UTC)
Your reading comprehension is horrendous:
You say "Robustness is a gratuitous buzzword"
I say "No, it's a technical term with a specific meaning"
You say "That does not mean we can gratuitously drop in the word robustness just because it sounds cool."
I say "When the hell did I ever drop in the word robustness? And, why, if you "know" that it's a technical term, would you ever claim that 'it's a gratuitous buzzword'?"
-- DanielPenfield (talk) 01:17, 1 May 2008 (UTC)
Robustness is a buzzword – do a google search for "robustness" and "buzzword" and you'll find plenty of people who agree with me. What makes it gratuitous is the fact that there was no context whatsoever to justify its use as a technical term here. Jayen466 09:44, 1 May 2008 (UTC)
You're both right. Robustness is used both as a buzzword and as a specific technical term (see e.g. robust statistics). As long as the text clarifies the intended meaning and why it is applicable here, it's fine. Dcoetzee 10:46, 1 May 2008 (UTC)
Thanks. For your reference, the text in question is reproduced above, at the beginning of this talk page section, in italics. That was all there was. It did not clarify the meaning, it didn't even mention the concept again. Jayen466 11:12, 1 May 2008 (UTC)


[edit] Structure

I think one of the big problems is the order of the sections. Here is the current status, and my commenst

Intro

Methodology

1.1 DMAIC

1.2 DMADV

1.3 Other Design for Six Sigma methodologies (this is absolute agony, does it really warrant third place?)

2 Implementation roles (dull, is this really important? Call yourself a Grand poobah for all I care)

3 Origin

3.1 Origin and meaning of the term "six sigma process"

4 Criticism (why is this so far up?)

4.1 Lack of originality

4.2 Studies that indicate negative effects caused by Six Sigma

4.3 Based on arbitrary standards

5 Examples of some key tools used (at long last, some content that somebody new to the topic might be interested in)

5.1 Software used for Six Sigma (incredibly boring detail for the average punter)

5.2 List of Six Sigma companies (mildly interesting)

6 References

7 See also

8 External links

So, let's try and get the information an intelligent, interested, but non expert reader would want up towards the start of the article, and leave the pedantic willy-waving to the end.

Intro

3 Origin

3.1 Origin and meaning of the term "six sigma process"

Methodology

1.1 DMAIC

1.2 DMADV

1.3 Examples of some key tools used (needs a para of explanation, some classification), not just a list of 50 year old statistics and fads.

5.1 Software used for Six Sigma

5.2 List of Six Sigma companies

2 Implementation roles

1.3 Other Design for Six Sigma methodologies

4 Criticism

4.1 Lack of originality

4.2 Studies that indicate negative effects caused by Six Sigma

4.3 Based on arbitrary standards

6 References

7 See also

8 External links

Just a suggestion Greg Locock (talk) 11:16, 1 May 2008 (UTC)

1.3 Other Design for Six Sigma methodologies (this is absolute agony, does it really warrant third place?) I am in favour of deleting that section. In fact, I had deleted it, but Daniel restored it. If it is kept at all, it should be somewhere near the end of the article. It is just empty words. Jayen466 11:23, 1 May 2008 (UTC)
I'd say that looks already better. A couple of points: The present content of the lede should go into the article proper, most of it probably to the history section, and we need a lede that actually does its job of summing up the article, in 2 or 3 paragraphs. The implementation roles are important, they're what (arguably) sets Six Sigma apart from the earlier initiatives. But I agree the present bullet format is incredibly dull. It needs a well-sourced, well-written paragraph that describes how a business managed according to Six Sigma works, and how this is different from more conventional management structures. Jayen466 11:31, 1 May 2008 (UTC)

[edit] Restructure

I have revised the article in line with Greg's suggestion above. Please review. It is still not a great article, but I hope it is a starting point from which we can improve further. Jayen466 19:21, 1 May 2008 (UTC)

I just reviewed your changes and the improvement is dramatic. This is much closer to an NPOV article. I endorse this revision strongly. Dcoetzee 22:51, 1 May 2008 (UTC)
Thanks. Jayen466 23:06, 1 May 2008 (UTC)
Yes that is heaps better. Greg Locock (talk) 02:03, 5 May 2008 (UTC)

[edit] Suspect math

I was curious about the section, 'Origin and meaning of the term "six sigma process",' and so I decided to run the numbers for myself. The figure of 3.4 x 10^-6 defects per opportunity coming from a specification limit 4.5 standard deviations away from seems, at first glance, to be incorrect. The probability of a normally-distributed random number being 4.5 or more standard deviations away from the mean is 3.93 x 10^-10 (figure calculated in MATLAB using the complementary error function; 2 * erfc(4.5)). Using the inverse complementary error function we should be able to find the right number of sigmas for a defect rate of 3.4 x 10 ^ -6; erfcinv(3.4 * 10^6 / 2) = 3.38. So, allowing for the arbitrary, unjustified 1.5 sigma cushion, maybe 6 sigma should be called 4.88 sigma?

If anyone else could verify that the figures provided in the article (3.4 DPMO corresponding to a specification limit 4.5 standard deviations away from the mean) are incorrect, that belongs on the Six Sigma page itself as a criticism. The whole thing reeks of a management process that claims some mathematical pedigree in operations or production research. Showing that the figures supposedly derived from the theoretical underpinnings of this idea are incorrect speaks a lot about the nature of this business management strategy.

In short, stop complaining about how bad the article is and start pointing out what's wrong with Six Sigma!

Additionally, one can trivially satisfy six sigma; just make the specification limit far enough away from the mean!66.17.137.1 (talk) 12:24, 8 May 2008 (UTC)

Tables showing cumulative normal probabilities give .9999966 for z = 4.50. 1 – .9999966 = .0000034 = 3.4 ppm. Also see the bottom table on this page, giving right-tail probabilities. Jayen466 13:33, 8 May 2008 (UTC)
So p(z>4.5) = 3.4 x 10^-6. But p(|z|>4.5) = 6.8 x 10^-6. 66.17.137.1 (talk) 18:11, 8 May 2008 (UTC)
It's unilateral, as it says in the text. The assumption is that the mean may wander off to one side. As soon as it does so, the figures for the other tail of the distribution become vanishingly small (cf. the table linked to above). Of course, if the mean remains completely stationary and just the standard deviation increases by a third, you'd get the same 3.4 ppm in each tail; but I reckon the Six Sigma guys would argue that empirically, that is not what tends to happen in practice. Jayen466 18:27, 8 May 2008 (UTC)

[edit] Literature section

Has there been any consideration to what the criteria are for inclusion in the 'Literature' section? It seems to be a rather random assortment of books, and has attracted at least one outright promotional addition. I'd usually attempt to prune it myself, but there are quite a few experts editing here, so I'll simply toss up the question. Kuru talk 00:18, 28 May 2008 (UTC)

I noticed the promotional addition as well (Six Sigma and Minitab). I reckon it should go. Otherwise, the list was based on the bibliography given in ref. 1, plus the work by Tennant that was cited in the article. IIRC, all the other works are American, and Tennant is UK; it's good to have at least one Brit in there. Jayen466 08:50, 28 May 2008 (UTC)