Talk:Six Sigma/Archive 5

2010 Discussion
I've added a section on criticism of the goal of reducing variation in some domains - based largely on work in the 1990's. If you have any new updates, please add them (and let me know).

ghol7955@gmp.usyd.edu.au

Criticism of the goal of reducing variation
In some processes, reduction of variation is essential. This is particularly the case when an average outcome is a successful one. It is also true in coordination games (cf. Thomas Schelling).

In some situations, an average outcome is a failure. This is particularly the case in races or tournaments with multiple highly skilled contenders where there is a disproportionate reward for being the best.

Business examples of tournaments include races for patents, other intellectual property, becoming the dominant player in an industry with positive network externalities (ex : social networking sites), setting an industry standard (ex : Microsoft windows, QWERTY keyboards).

Organizational examples of tournaments include contests for promotion.

In such situations, there may be a substantial benefit to increasing - not reducing variance. In fact it may be useful to sacrifice some mean performance to increase variance [Holt and Gaba 1995] This area has been initially examined in the statistical field of stochastic control. Some early work has also been done by Lola Lopes a decision scientist.

For intuition consider a tournament where a large prize goes to the best player (for example the first to patent an invention in an area) and the rest lose. Consider a tournament with 10 players with a mean value on some performance measure of 0 and a standard deviation of 1. Each has a 1 in 10 chance of winning. Now consider what happens if one player sacrifices some mean performance to massively increase variance - for example a mean of -1 with a standard deviation of 100. That player now has approximately a 50 % chance of winning the tournament - a major improvement.

Now consider a player who implemented Six Sigma and effectively reduced their standard deviation to near zero. This player has now nearly no chance of winning the tournament.

As a practical matter, this is particularly a problem for industries which require and reward a high level of innovation, where challenges are difficult and rewards tend towards "winner take all" rather than proportional. (Intellectual property for example). In these areas six sigma can be directly counterproductive by reducing creativity, innovation and the variation necessary to win.


 * There are at least three problems with your contribution:
 * It appears to be WP:OFFTOPIC
 * It appears to be original research
 * I can't verify the one source you provide ("Holt and Gaba 1995") through Google scholar or Worldcat
 * -- DanielPenfield (talk) 17:15, 12 February 2010 (UTC)

This is clearly not WP:OFFTOPIC, far above the quality of the rest of the article, not original research but simple logic with an illustrative example. It is a bit too long, perhaps, but it is essential that this obvious limitation of six sigma should be in the article in some form. Six sigma' core idea is not applicable to anything other than standardization of static, well defined processes, and applying it to anything that demands originality, creativity, flexibility, responsiveness to conditions that rarely repeat or winner-take-all type situations will result in a worse outcome than if it had not been used, and the above section makes it intuitively mathematically clear why this is so. Enon (talk) 09:01, 24 September 2010 (UTC)


 * In the sciences, the six-sigma approach encourages "incremental research". Incremental research is a sign of a mediocre or lower-grade scientist.Dogface (talk) 19:20, 23 December 2010 (UTC)

one sigma vs. six sigma
If one sigma is 31% in this article, someone should specify how these sigmas are different from statistical sigmas where one sigma is around 68% of a population. KTHX. —Preceding unsigned comment added by 70.238.168.175 (talk) 02:18, 10 May 2010 (UTC)


 * It's one sigma total on either side of the target; not one sigma on each side. Basically a half sigma in each direction.  There's a chart on page 17 here that probably illustrates it better than I can explain.  Kuru   (talk)  00:20, 12 May 2010 (UTC)

I was confused as well by the assertion that only 31% of parts in a 1 sigma process are error free. It only makes sense within the (much) later discussion wherein the mean is shifted by 1.5 sigma. To state the 31% result without reference to the 1.5 sigma shift is confusing to those of us who aren't already black belts. —Preceding unsigned comment added by 67.242.251.26 (talk) 19:14, 6 June 2010 (UTC)
 * Yes, this seems to cause confusion often. It's covered in the "Role of the 1.5 sigma shift" section here, but probably needs to be footnoted in the preceeding sections which will trip up other math majors.  Kuru   (talk)  15:33, 28 June 2010 (UTC)

That table is frankly terrible and needs to be fixed, preferably by someone who both understands standard deviations on a normal curve as well as how six sigma uses it. If the goal is to look at P(X>Xbar+s) then that needs to be written down. The current description where 69% is considered to be beyond 1 sigma doesn't make much sense(seeing as 1 standard deviation is 68.2 % of the population). If it's one directional that has to be explicitly stated as many people use 2-sided specs. Urgh.

Also, the assumption of normality shouldn't just be mentioned in the criticisms but in the definition of the system. That's not a small assumption. —Preceding unsigned comment added by 158.35.225.229 (talk) 16:25, 18 May 2011 (UTC)

First footnote
The first referenced footnote says that it was developed by Motorola in 1981, yet I cannot find anything in the book cited in the reference to support that. -Deathsythe (talk) 17:38, 26 May 2010 (UTC)

1981 or 1986
The intro cites 1981 at the beginning of Six Sigma but the first section cites 1986. Let's find out which is correct 12.151.151.3 (talk) 22:47, 1 June 2010 (UTC)

Should be 1986. Motorola celebrated 20 years of Six Sigma in 2006. There was an article in iSixSigma Magazine Jan/Feb 2007 that talks about the history in some detail. see http://www.isixsigma-magazine.com/archive/default.asp?vol=3&num=1 —Preceding unsigned comment added by Huesing (talk • contribs) 11:37, 7 June 2010 (UTC)

Should be 1986. I just wrote a short description of Six Sigma under Total Quality Management. We have also created a link to Six Sigma. Please feel free to drop by there to contribute on TQM if you are also familiar with that field. Mikebeep (talk) 21:55, 27 November 2010 (UTC)

References Section
References 26 and 27 are missing. It appears they were there, and are still in the article, but not at the bottom of the page. Anyone know how to fix this? —Preceding unsigned comment added by 174.21.185.42 (talk) 09:45, 5 March 2011 (UTC)

Isn't there any criticism?
This sort of crap is a load of horse-shit, invented by idiots who have little to do and a lot of time on their hands, to invent garbage ideas to 'prove' their worth. Is there no criticism of this utter, absolute nonsense? it is used for the process improvement and helps in organization maturity — Preceding unsigned comment added by 58.27.146.128 (talk) 15:32, 19 June 2011 (UTC) It has also been shown to save a remarkable amount of money for companies who have successfully implemented it. Like other quality methodologies, its value is only as good as its champion's commitment. — Preceding unsigned comment added by 8.28.72.250 (talk) 19:52, 14 November 2011 (UTC) PLEASE STOP CALLING SIX SIGMA A "STRATEGY." IT IS NOT A STRATEGY. IT IS AN EFFICIENCY IMPROVEMENT PROCESS. — Preceding unsigned comment added by Skridgley (talk • contribs) 02:40, 24 February 2012 (UTC)


 * Large public companies are basically required to claim tangible results for unmeasurables. It's only remarkable that people take these reports of savings as actionable information. [ bÐ i (116.97.108.107) 03:37, 13 November 2013 (UTC) ]

Total Failure
Does anyone else notice that before Six Sigma, Motorola were a microprocessor developer beloved by all, but since then they've become a shit phone company?


 * I think that's probably because the microprocessor development arm spun off as Freescale, which not because of anything SS did Cmactaggart (talk) 18:10, 15 August 2013 (UTC)

Yup, I think that just about sums the whole thing up, contributor. It's all a load of twaddle, job creation for many though ! The (American parent) company I worked for was, and probably still is, heavily into Six Sigma and steadily declined over a decade or so due to poor management. Interestingly, most of the management that moved on were SS black belts ! Cabinscooter (talk) 07:50, 10 December 2010 (UTC)

2011 Discussion - Certification
Unlike Project Management, HR or ROI Methodology, ix Sigma does not have a standard certifying body, there are several different organizations that certify individuals who complete the courses.

Based on this I added one of the recognized institutions that offers courses and certifications to those interested in Six Sigma training (green, black, master belts).

The link was removed the following day and tagged as commercial. I understand the desire to remove spammy links from the pages, but this is a legitimate university with a distinguished reputation and an online option, as many universities are moving to offer.

If you feel the link should not be included, that's ok. I feel it adds another option for those seeking professional education. — Preceding unsigned comment added by GoBlueWhite (talk • contribs) 19:21, 8 March 2011 (UTC)


 * Hi. It is certainly promotional to me, you are promoting this website as an authority on the subject.Pm master 10:03, 9 March 2011 (UTC)
 * The best solution is to restrict ourselves to certification bodies mentioned in independent reliable secondary sources. -- J N  466  22:29, 20 September 2011 (UTC)
 * This is still ongoing, with a number of prominent and not so prominent firms being added and re-added without independent, secondary sourcing. . That is not okay. The ASQ and IQF are there by rights; they are mentioned as certifiers in many, many secondary sources that are independent of them. The cited book mentions the Juran Institute, Qualtec and Air Academy, which are also frequently mentioned in the literature. No others should be added without a secondary source, and evidence that they are at least equally prominent in the literature. Otherwise we will end up with a list of 50 companies, down to the Six Sigma trainer working from his garden office. -- J  N  466  23:08, 12 July 2012 (UTC)

Only in the US?
Are there no certification or university pograms outside the US? — Preceding unsigned comment added by 74.15.40.164 (talk) 14:44, 24 July 2013 (UTC)

30 Rock
Is it worth mentioning in this article that Six Sigma was frequently satirized in the show 30 Rock and that the character Jack Doughnagy was an ardent adherent of Six Sigma? — Preceding unsigned comment added by Tjc (talk) 06:30, 14 November 2014‎ (UTC)
 * This little factoid was added back in March 2010 and almost immediately deleted. -- DanielPenfield (talk) 10:40, 23 July 2015 (UTC)

Restoring Crosby quotation
An editor deleted an entire short section, Inadequate for complex manufacturing, with the edit comment: "(Six sigma is an approach, not a standard. Someone who thinks all organisations should aim at 3.4 defects per milion has not got the basic idea.)" This amounts to saying "I removed verifiable sourced material about Philip B. Crosby's opinion, because I don't think Crosby understands Six Sigma."

That's not a good reason to remove it. Wikipedia allows "facts about opinions" and it is a fact that Crosby has expressed that opinion. The founder of Zero Defects IMHO is an important enough authority that his opinion is relevant. If there's a verifiable source who in turn criticizes Crosby's comment, a quotation from that source could be added to the section, under the neutrality policy. But we shouldn't delete verifiable, properly sourced material on the basis of an editor's personal opinion that Crosby does not understand Six Sigma.

Dpbsmith (talk) 00:23, 15 August 2016 (UTC)
 * Also, per Reliable sources and undue weight, "Neutral Point of View says that the article should fairly represent all significant viewpoints that have been published by a verifiable source, and should do so in proportion to the prominence of each." and furthermore Let the reader decide. BTW, I'm sure Crosby understood Six Sigma, but, like TQM, it was a threat to his own Zero Defects/Make Certain "concepts" and thus the fear, uncertainty and doubt.  Regardless, I'd argue, as you do, that any relevant pronouncement about the subject of the article by any of the "quality gurus" is important for readers to be aware of.  -- DanielPenfield (talk) 07:26, 15 August 2016 (UTC)


 * From Doctrine, in this article. "Six Sigma's implicit goal is to improve all processes, but not to the 3.4 DPMO level necessarily. Organizations need to determine an appropriate sigma level for each of their most important processes and strive to achieve these." So the quote from Crosby shows that he was setting up a straw man to knock down.  Self-contradictory articles are not what WP is about, so you either need to deliver a much more nuanced discussion of why Crosby was writing bullshit, or allow your section to be deleted.  Personally, I suspect it was a typo in his book: what makes sense is a wish to argue against a six sigma standard, (no capitals, no quotation marks), but according to the ref the comment was against a "Six Sigma" standard.  The first choice would merely say that in certain cases the standard needs to be (better than six) sigma, which is an uncontentious observation about a choice of statistical result to be desired, but which has no place as criticism of "Six Sigma" in this article.  By capitalizing and enclosing in quotes he's referring to the "Six Sigma" approach to process improvement, and if he intended that he was completely, and obviously, wrong.
 * Further, please don't paraphrase my words with your understanding of them, and then attack the paraphrase. That's the same strawman error that Crosby is guilty of in the quote, but as mentioned, I think his error was an accidental typo.
 * Gravuritas (talk) 07:44, 15 August 2016 (UTC)
 * {| class="wikitable"

! Your claim !! My response
 * From Doctrine, in this article. "Six Sigma's implicit goal is to improve all processes, but not to the 3.4 DPMO level necessarily. Organizations need to determine an appropriate sigma level for each of their most important processes and strive to achieve these." || I think we're all aware of that. The point that you seem to have missed is that Crosby is of such a stature in the area of quality management that his views should be included regardless of whether we agree with them or not.  See WP:Verifiability, not truth and WP:NOTCENSORED
 * So the quote from Crosby shows that he was setting up a straw man to knock down. || No, it shows that he wasn't afraid to take repeated swipes at methodologies that competed with his own.
 * Self-contradictory articles are not what WP is about, so you either need to deliver a much more nuanced discussion of why Crosby was writing bullshit, or allow your section to be deleted. || "Delivering a much more nuanced discussion" is exactly what nobody should be doing. See WP:NOTESSAY and WP:NOR.
 * Personally, I suspect it was a typo in his book: what makes sense is a wish to argue against a six sigma standard, (no capitals, no quotation marks), but according to the ref the comment was against a "Six Sigma" standard. || The reference that you deleted contains a link to WorldCat, specifically this link, so that you can find a copy of the book in a local library and verify for yourself.
 * The first choice would merely say that in certain cases the standard needs to be (better than six) sigma, which is an uncontentious observation about a choice of statistical result to be desired, but which has no place as criticism of "Six Sigma" in this article. || Not that it's relevant to the question of censoring Crosby's criticism, but do you have a WP:RS for this? Providing a reliable source for this claim can only strengthen the article and help WP:Let the reader decide the validity of Crosby's criticism.
 * By capitalizing and enclosing in quotes he's referring to the "Six Sigma" approach to process improvement, and if he intended that he was completely, and obviously, wrong. || No, he's very definitely criticizing Six Sigma directly. BTW, he also badmouths ISO 9000, the Malcolm Baldrige National Quality Award, and Total quality management.
 * Further, please don't paraphrase my words with your understanding of them, and then attack the paraphrase. That's the same strawman error that Crosby is guilty of in the quote, but as mentioned, I think his error was an accidental typo. || Err, you do know that you're address two distinct editors, right? Also, instead of reverting out-of-hand, why don't you visit your local library and see if you can actually borrow and read the book (directly or through inter-library loan)?
 * } -- DanielPenfield (talk) 11:23, 15 August 2016 (UTC)
 * The first choice would merely say that in certain cases the standard needs to be (better than six) sigma, which is an uncontentious observation about a choice of statistical result to be desired, but which has no place as criticism of "Six Sigma" in this article. || Not that it's relevant to the question of censoring Crosby's criticism, but do you have a WP:RS for this? Providing a reliable source for this claim can only strengthen the article and help WP:Let the reader decide the validity of Crosby's criticism.
 * By capitalizing and enclosing in quotes he's referring to the "Six Sigma" approach to process improvement, and if he intended that he was completely, and obviously, wrong. || No, he's very definitely criticizing Six Sigma directly. BTW, he also badmouths ISO 9000, the Malcolm Baldrige National Quality Award, and Total quality management.
 * Further, please don't paraphrase my words with your understanding of them, and then attack the paraphrase. That's the same strawman error that Crosby is guilty of in the quote, but as mentioned, I think his error was an accidental typo. || Err, you do know that you're address two distinct editors, right? Also, instead of reverting out-of-hand, why don't you visit your local library and see if you can actually borrow and read the book (directly or through inter-library loan)?
 * } -- DanielPenfield (talk) 11:23, 15 August 2016 (UTC)
 * Further, please don't paraphrase my words with your understanding of them, and then attack the paraphrase. That's the same strawman error that Crosby is guilty of in the quote, but as mentioned, I think his error was an accidental typo. || Err, you do know that you're address two distinct editors, right? Also, instead of reverting out-of-hand, why don't you visit your local library and see if you can actually borrow and read the book (directly or through inter-library loan)?
 * } -- DanielPenfield (talk) 11:23, 15 August 2016 (UTC)
 * } -- DanielPenfield (talk) 11:23, 15 August 2016 (UTC)

Commentary under graph, formula for DPMO
I changed the wording under the graph (it's not important if it's an inflection point) and added a formula for DPMO to match the "double checked and well-sourced" numbers in the table. I'd be grateful if any six-sigma advocates could check I didn't trample on any vital niche meaning of "inflection" and would be great if there was a reference for the formula we could use. Kind regards all. 82.69.229.22 82.69.229.22 (talk) 15:00, 10 February 2017 (UTC)

Wiki Education Foundation-supported course assignment
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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 09:25, 17 January 2022 (UTC)

Intro muddle
"A six sigma process is one in which 99.99966% of all opportunities to produce some feature of a part are statistically expected to be free of defects. "

What the heck is an "opportunity to produce some feature"? Is this sentence saying something different from simply "A six sigma process produces less than 3.4 defects per million units"? Gwideman (talk) 12:06, 12 January 2019 (UTC)

This article appears as if there is some standardization to what Six Sigma is and there is none. The terms Yellow Belt, Green Belt, Black Belt, Master Black belt do not hold any special role or knowledge differential. I also did not see any mention of White Belt.

Seeking guidance.
Since the beginning of 6 sigma, we have wholesome implementation of Law of Adaption & Law of Alignment. But that applied to my adaptation when Darwin was at Value X. Talking and Trying to do an A3/A4 for 6 sigma for current life scenario.. Where orgs are spending more on social and tech and less on Economical values.. Why we not put Law of Communication a enough sphere of existence in the whole system. I believe I am talking more Agile and less of 6 sigma but I researched a bit, I dont see much on Law of Communication as direct contributor. They might come at a later part but not from an umbrella approach.

If any resources, please share.. I would like to read and co-relate. If I am wrong too, please correct. 2402:3A80:91E:FEE9:0:62:77BB:1 (talk) 16:17, 17 January 2022 (UTC)