Control Charts (Non-normal Distribution)

I agree nobody, including yourself, tried to solve the cases.  As I’m sure others will tell you, the usual procedure on this site is for you to try to solve the problem, post a reasonable summary of your efforts on a thread and then ask for help/suggestions.

@Darth pointed you in a direction and gave you a reference.  Given what he offered your approach should have been to get a copy of the book referenced, learn about G and T charts, and do the work manually. Agreed it would have taken more time than if you had a program handy but by doing things manually (at least once) you would have learned a great deal and also solved your problem.

What an IMPRESSIVE retort!!!  @fausto.galetto DO YOU appreciate the INEFFABLE TWADDLE of this entire thread (see, I can yell, insult, and boldface type too) ?

Let’s do a recap:

1. OP initial post says he wants a solution for two items in an attached document.

2. I do a quick skim and offer the comment that I think the correct venue for the OP would be a peer reviewed paper since it certainly looked like a challenge to the authors/papers cited.

3. The OP responds and assures me this is not the case – all he wants is for some generic six sigma master black belts to provide a solution. Given what follows later it is obvious he doesn’t want a solution – just confirmation of his views.

4. @Darth offers a suggestion and a recommendation to try running Minitab – and in the following OP post @Darth gets slapped down for his suggestions.

5. Reluctantly, the OP announces he has downloaded Minitab “BECAUSE NOBODY tird to solve the cases”

6. The OP then lays into Minitab on this forum because “MInitab does not provide the Theory for T Chart….

BETTER I DID NOT FIND in Minitab the THEORY!!! IF someone knows it PLEASE provide INFORMATION”

7. @Darth tries again with a Minitab analysis and provides a graph of the results – the OP slaps him down again.

8. The OP shifts gears – suddenly, somehow, the OP knows “MINITAB makes a WRONG analysis: the Process is OUT OF CONTROL!!!!!!!!!!!!!!!!!! I asked to Minitab the THEORY of T Charts!!!!!

9. The OP then slams me for stating he hasn’t tried to solve the cases. OK, fine, I’ll assume he did try. I probably should have said the OP hadn’t tried to do any research with respect to finding the theory of T control charts or really understanding anything about them other than insist Minitab drop everything and get back to him with the demanded information pronto! – but this really doesn’t matter because, as one can see in the other posts, the OP KNOWS Minitab is wrong because he has a proof based on THEORY!  What theory he doesn’t say but apparently it doesn’t matter since this THEORY is better than the THEORY of T Charts – even though, by his own admission, he doesn’t know what that theory is.

Given the bombast I decided to see what I could find.  I couldn’t find a single peer reviewed paper by the OP listed in either Pubmed or Jstor.  Granted there are other venues but these two happen to be open to the public and are reasonably extensive.

I did find a list of papers the OP has presented/published at various times and I found some vanity press (SPS) – publish on demand books by the OP – of the group I found the title of his book  “The Six Sigma HOAX versus the Golden Integral Quality Approach LEGACY”  interesting because the title, as it appears on the illustrated book cover on Amazon, is written in exactly the same manner as the OP’s postings.  Given the book title I find it odd that the OP would ask anyone on a Six Sigma site for help. After all, with a title like that one would assume the OP views practitioners of Six Sigma as little more than frauds and con artists.

In summary – the OP believes he has found Minitab to be in error and he wants some generic master black belts to confirm his belief.  I do know the folks at Minitab really know statistics and process control. I also know many of the statisticians at Minitab have numerous papers in the peer-reviewed press on statistics and process control and have made presentations at more technical meetings than I could list.  Under those circumstances, if the OP really thinks he is right and Minitab is wrong then the OP first needs to take the time to find, and thoroughly understand, the theory behind the T chart – this would require actually researching the topic – books, peer reviewed papers, etc.

In science, extraordinary claims require extraordinary proof and the burden of the proof is on the challenger, not on those being challenged.  If, after doing some extensive research,  the OP is still convinced he is right then the proper venue for a challenge of this kind is publication in a peer reviewed journal that addresses issues of this sort.

In his initial post, Fausto asked: “I would like to get solution to the cases shown in the file.”

In my position, I often find that people often want me to do their schoolwork for them.

I agree with Robert Butler, ranting about THEORY without offering a competing, well-documented theory is non-productive.

Oh well, in for a penny in for a pound.

@fausto.galetto – great – so now you have completely contradicted your denial of the comments I made in my first post.

I said the following:

/////

1. A quick look at the file you have attached strongly suggests you are trying to market your consulting services – this is a violation of the TOS of this site.

2. If you want to challenge the authors of the books/papers you have cited, the proper approach would be for you to submit your efforts to a peer reviewed journal specializing in process/quality control.

/////

To which you responded:

/////

Dear Robert Butler,

NO CONSULTING SERVICES TO BE SOLD!

I am looking for solutions provided by the Master Black Belts (professionals of SIX SIGMA).

I do not want to challenge the authors!!!

THEY did not provide the solution!!!!!!!!!!!!!!

I repeat:

I am looking for solutions provided by the Master Black Belts (professionals of SIX SIGMA).

/////

…and what followed was a series of posts that demonstrated you were indeed challenging authors and you were not looking for solutions since, by your own admission, you had already solved them and you thought they were wrong and you were right.

So today you post what amounts to an advertisement for your services/training. True, you don’t specifically encourage the reader to purchase anything but the only reference is to you and your publication and the supposed correctness of your approach.

A couple of asides:

1. You say “Since then THOUSANDS of MASTER Black Belts have been unable to solve the cases.”

a. And you determined this count of “Thousands” how?

b. Why would the fact that “Thousands” of MBB’s have been unable to solve the cases in the way you think they should solve it matter?

c. Given you are challenging the the approach of various authors of books and papers what makes you think your version is correct?

d. I only ask “c” because one can find out on the web your proof of the “so-called Riemann Hypothesis” – your words – submitted to some general non-peer reviewed archive on 5 October 2018 which was incorrect (in a follow up article to the same archive you said it was “a very stupid error”). It would appear, even with this correction the proof was still wrong because, according to Science News for 24 May 2019, the proof of the Riemann Hypothesis (or conjecture) is still in doubt.  The article states “Ken Ono and colleagues” are working on an approach and a summary of their most recent efforts can be found in the Proceedings of the National Academy of Sciences.

2. It’s nice that Juran praised one of your papers at a symposium – the big question is this – which peer reviewed journal published the work?

The original focus of this exchange was the issue of the validity of the underpinnings of the T-chart.  Your conjecture is that you have developed a theory and this theory is correct and the, apparently to you, unknown theory behind the T-chart is wrong.  Your approach to “proving” this is to

1. Ask for a bunch of MBB’s to provide a solution to problem(s) you have posed with the understood assumption that if they don’t exactly reproduce your results then they are wrong.

2. Demand that the folks at Minitab provide the underlying theory of the T chart and along the way prove you are wrong.

As I said in an earlier post to this exchange – extraordinary  claims require extraordinary proof and the burden of the proof is on the individual making the claims not on the people against whom the claims are made. I sincerely doubt you will hear anything from Minitab for the simple reason that, to the best of their knowledge, (as well as to the best of the knowledge of anyone who might be using their T-chart program for process control) what they have is just fine.

It really doesn’t matter what you think about whatever theory you have built nor does it matter that you think you have done whatever it is that you have done correctly.  The issue is this – do you have a “reasonable” amount of actual data where you can conclusively show the following:

1. Specific instances where the Minitab T-chart control declared a process to be in control only to find that it really wasn’t in control and when your approach was applied to the same data, your approach identified the out-of-control situation.

2. Specific instances where the Minitab T-chart control declared a process in control, it was found to be in control, and when the data was analyzed with your approach you too found it to be in control.

3. Instances where your approach declared a process to be out-of-control only to find later it was not out-of-control and, when the data was re-analyzed with the Minitab T-chart, their methods identified the process as in control.

4. Instances where your approach declared the process to be in control only to find it was out-of-control and when checked with the Minitab approach the out-of-control situation was correctly identified.

5. …and, once everything is tallied – what kind of results do you have – a meaningful improvement in correct identification of out-of-control situations when dealing with processes needing a T-chart (while simultaneously guarding against increases in false positives) or just some kind of change that, in the long run, is at best, no better than what is currently in use.

You have made a big point about citing some of Deming’s statements concerning theory.  Although I can’t recall a specific quote, one big point he made was the need for real data before you did anything else.  His book Quality, Productivity, and the Competitive Position is essentially a monument to that point.  What you have presented on this forum is a theory bereft of evidence – just claiming everyone else is wrong because it violates your personal theory is not evidence.  The kind of evidence you need is as listed in the four points above.  If you have that kind of evidence and if what you have appears to be a genuine improvement,  then, as I’ve said before, the proper venue for presentation is to a peer reviewed journal that deals in such matters.

In this light, your rebuttal concerning “thousands” is without merit.  The point of this thread was that the Minitab T-chart method was wrong and nothing more and it was in this context that you made the claim that “thousands” of MBB’s were wrong.  The “proof” you provided in your most recent thread is based on a claim that the entire Minitab analysis package is wrong. In addition, in an attempt to inflate the “thousands” estimate, you dragged in poor old Montgomery and declared his book has BIG errors.  Statements such as these are not proof – they are just simple gainsaying.

Now, what to do about the rest of your last post?

1.  Your rejoinder concerning the Riemann Hypothesis is standard misdirection boilerplate – the fact remains that if your proof had had any merit it would have made the pages of at least one of the journals on mathematics.

2. How many people have I seen who have admitted a mistake in a publication?  Quite a few – you can find corrections and outright retractions with respect to papers in peer reviewed journals if you take the time to go looking for them.  One good aspect of the peer review process is that the vast majority of mistakes are found, and corrected, before the paper sees publication.

I happen to know this is true because I do peer reviewing for the statistics sections of papers submitted to one of the scientific journals. I can’t tell you the number of mistakes in statistical analysis I have found in submitted papers.  As part of the review process what I do is point out the mistake(s), provide sufficient citations/instructions concerning the correct method to be used, and request the authors re-run the analysis in the manner indicated.  The length of the written recommendations varies.  The longest I think I’ve ever written ran to almost two full pages of text which were accompanied by attachments in the form of scans of specific pages in some statistical texts.  In that instance the authors re-ran the analysis as requested, were able to adjust the reported findings (most of the significant findings did not need to be changed, a couple needed to be dropped, and, most importantly, they found a few things they didn’t know they had which made the paper even better), addressed the concerns of the other reviewers and their paper was accepted for publication.

3.  In my career as a statistician, more than 20 of those years were spent as an engineering statistician in industry supporting industrial research, quality improvement, process control, exploratory research, and much more.  I too did not have time to send articles in for peer review and I too made presentations at conferences.  Some of those presentations were picked up by various peer reviewed journals and, after some re-writing for purposes of condensation/clarification saw the light of day as a published paper. It was because of my experience that I asked about yours.  I thought the question was particularly relevant in light of your position concerning your certainty about the correctness of your efforts.

4. As for reading you archived paper on peer review – no thanks.  I seem to recall when I checked you had uploaded more than one paper on the subject of peer review to that site and, if memory serves me correctly, all of them had titles suggesting the text was going to be nothing more than a running complaint about the process.

The peer review process is not perfect and can be very stressful and frustrating – I know this from personal experience.  Sometimes the intransigence of the reviewer is enough to drive a person to thoughts of giving up their profession and becoming an itinerant  beachcomber.  However, based on everything I’ve experienced, the process has far more pluses than minuses and, given the inherent restrictions of time/money/effort of the process, I have yet to see anything that would be a marked improvement.

Is this twitter? :)

Happy new year to my buds such as @mike-carnell and @rubtler and @darth

@fausto.galetto please leave me off your post. I have zero interest in your self-aggrandized esoteric ramblings.

New account, old timer chiming in.

I’m just going to add some general big picture comments here.

With n=20, distribution fitting and parameter estimation isn’t going to be very accurate, but it can still be useful.

In my experience using automated distribution fitting you need thousands of data points to consistently select the theoretically correct distribution.

Also for t charts in Minitab you can choose Weibull or Exponential.  Personally I think one should always use distribution fitting for control charting but t charts got their popularity boost on health care as a simple approximate way to deal with their non normal data.

There is no “hidden theory”.  Joel Smith has a good paper on t charts in JQT.  Control charts for Nonnormal data are well documented.

Finally, if you have a known distribution then obviously use that.  However that is rare.

• This reply was modified 2 months, 1 week ago by David007.

It’s least squares, not Maximum Likelihood for the T charts, if  there is a 0:

https://support.minitab.com/en-us/minitab/19/help-and-how-to/quality-and-process-improvement/control-charts/how-to/rare-event-charts/t-chart/methods-and-formulas/methods-and-formulas/

• This reply was modified 2 months, 1 week ago by David007.

The exponential T charts use an exponential distribution and use maximum likelihood to solve the parameter.  This is exactly equivalent to the control chart obtained when doing a Nonnormal capability six pack with an exponential distribution.

Minitab didn’t invent the T charts. They became popular in health care so they added the tool.

If you are saying the chart fails to detect assignable causes, try simulating some exponential data.

The T chart (Exponential) doesn’t show OOC but MR does if you use Non Normal Capability Six Pack (Exponential)

PS In order to determine if a method is correct or not correct you need to do thousands of simulations, and look at alpha. Add power study then even more.

You really should play with some simulated exponential data. You’ll be surprised by what you see as “inherent variation”.

Fyi, we always tell people that if a process is non-normal due to outliers then deal with those, don’t use transformations or a Nonnormal distribution.

However the processes being discussed here are inherently non normal with an exponential distribution.

Effectively by defining a process like this as “out-of-control” you are sending your clients on a wild goose chase looking for assignable causes when there are none to be found.

If any theory coming from process expertise is available then, of course, use it.  In the examples discussed we were given that it was an exponential distribution, so control limits based on an exponential distribution should be used.

Generally however, with n=20, any distribution identification is going to be an approximation.  So the model is wrong, but can still be useful.

And by the way simulations are sometimes the only way to determine optimal methodology. Take for example, computing the threshold parameter of a Weibull distribution.  Given a particular shape, should you use maximum likelihood, iterative bias reduction or maximum product spacing?  Try solving that with theory. Good luck.

> With millions of simulations one can find that the MINITAB T CHARTS are WRONG 93.3% of “applications”

Sure if the underlying distribution is something other than an exponential (or Weibull) distribution, say an application with a lognormal or loglogistic distribution. That’s why we do distribution identification with probability plots.

Strange that Six Sigma is 34 years old and yet continues to be used with success. I guess we’ve been duped all this time /s.

Post a white paper to prove your point.

Minitab tech support is not needed. Calculate the scale (Exponential) or scale and shape (Weibull) using maximum likelihood. Compute .135 and 99.865 percentiles.

• This reply was modified 2 months ago by David007.

Hey Katie,

Maybe time to close this thread.  This Fausto guy is really a whack job.  He will not be convinced so maybe Chris, Robert and David can stop humoring him and he will go away.  Hope all is well with you and Fake Mike.

@fausto.galetto As I previously explained, self-promotion (which includes listing your published articles/linking to your content) is not permitted in the forum. You’re welcome to include as much of this information as you’d like in your User Profile.

@fausto.galetto “Pease refer to my User Profile for details on my previously published works.”

@fausto.galetto – In your post to @David007 on February 29 at 4:39 AM you spewed out a lot of hate and you concluded with the statement “Tell me your publications SO THAT I CAN READ them…. and I will come back to you and to your “””LIKERS”””!”

@David007 has been courteous and polite in every response he has made to your postings.  Your responses to his posts are nothing but shouting and invective. They are, by turns, irrational, ugly, viscous, denigrating, and hateful.  They have no place on a forum of this type.

The following statements – (I won’t bother to bold them since you have already)

1. “There is no “hidden theory”. Joel Smith has a good paper on t charts …Control charts for Nonnormal data are well documented”

2. “is your issue that the data is neither exponential nor Weibull, but something else?”

3. “If you are saying the chart fails to detect assignable causes, try simulating some exponential data.”

4. “But as I’ve repeatedly said with n=20 the model is going to be wrong anyway.”

5. “You really should play with some simulated exponential data. You’ll be surprised by what you see as “inherent variation””

6. “Minitab tech support is not needed. Calculate the scale (Exponential) or scale and shape (Weibull) using maximum likelihood. Compute .135 and 99.865 percentiles.”

7. “I anxiously await to see your rebuttal paper in any of Quality Engineering, Journal of Quality Technology, Technometrics, Journal of Applied Statistics, etc.”

8. “along with your spam practice”

are not goads, are not impolite, and they most certainly are not “IGNORANCE, INCOMPETENCE and PRESUMPTUOUSNESS” as those words are generally understood.

To goad is to provoke someone to stimulate some action or reaction – there is nothing provocative in any of the cited quotes. A rational assessment of the 8 quotes cited above is as follows: 1-6 are just plain statements of fact and/or polite questions concerning your take on the issue – nothing more.  #7 is a very polite and logical response to all of your posts that preceded it.  And #8 is an objective observation concerning your posting practice.

In your numerous posts to this thread you have made it very clear you interpret anything that goes against your personal views as arising from “IGNORANCE, INCOMPETENCE and PRESUMPTUOUSNESS”. What you choose to ignore is the obvious fact that your personal views are not shared by the people you are addressing on this forum, by the body of practitioners of science/engineering/process control in general, nor by the body of reviewed and published scientific/engineering literature.

Look, if you said something like parameter estimation issues due to small sample size, or the issues with transformation (debated extensively in the past – Wheeler versus Breyfogle), we could have a civil conversation/debate. But you are just trying to sell your book.

@fausto.galetto – sorry, I’m with @David007 on this one.  Your latest response(s) to me (and to him) are true to form – invective and shouting.  I know this is just poking the Tar Baby and prolonging a very sad string of posts at the top of the masthead of a very good site, but you really should re-read what you wrote and contrast that with my last post. There is nothing in any of the 8 statements you cited that have anything to do with THEORY – as you are so fond of putting it.

Given your violent reaction to anything you perceive as contrary to your views, I actually took some time to look over some of the numerous things you have uploaded to that storage site ResearchGate.  I also took some time to check out the reputation of that site. Three things are immediately evident:

1. The noble concept of “open access” is DOA and you are taking the life of your grant and the status of your professional reputation/career in your hands if you try to use anything on those sites as a basis/starting point for your work.

2. If the “paper” you sent to  Quality Engineering looked anything like the stuff you have uploaded to that storage site (open access with no apparent oversight) it is not surprising it was rejected.

3. Based on what you have posted here and on ResearchGate it appears you strongly favor the PBV method of scientific discourse (Proof By Volume).  That method works well in the world of politics and extreme religious movements but does not advance your cause (and hopefully it never will) in the world of engineering and science.

As I noted in my post to your thread yesterday your situation is exactly that described by Abraham Kaplan and you have confirmed this to be the case in your post where you specifically stated:

“For me THEORY is

·              ·         The set of all LOGIC Deductions

·              ·         Drawn

·              ·         From Axioms and Postulates

·              ·         Which allow to go LOGICALLY from Hypotheses to Theses

·              ·         Such that ALL Intelligent and Sensible people CAN DRAW the SAME RESUL”

So, to reiterate – what you have is a pure theory which has no basis in empirical fact and which is, as you are so fond of saying – wrong.  What is particularly interesting about your situation is that you have conclusively proved you are wrong and you have demonstrated that fact time and again.

In the scientific world when one constructs what they believe to be a new theory the very first thing they do is make sure their theory is capable of accounting for all of the prior known facts in whatever area it is they are working.  Montgomery’s work, the methods and results of T Charts, etc. have been around for a long time and have withstood the close scrutiny and testing by myriads of scientists, engineers, statisticians, health practitioner, etc.  No one has found anything wrong with them.

If a real scientist constructs a theory and finds it at odds with prior known facts the first thing that individual will do is choose to believe there is something wrong with the theory and spend time either trying to adjust the theory to match the known facts or, if that proves to be impossible, scrap the theory and start over.  In your case, you tested your theory and found it at odds with Montgomery et.al. and came to the instant conclusion your theory, based on a set of axioms and postulates of your choosing, was correct and everyone else was wrong.

As Kaplan noted – the world your theory has deduced will only mirror reality to the extent that the premise mirrors reality. The empirical evidence you have compiled in your uploaded rants about MINITAB and Montgomery’s text repeatedly confirm the fact that your theory (and most certainly the postulates and axioms upon which it is based) does not mirror reality and is therefore wrong.

Instead of recognizing this very obvious fact you have chosen to spin the failures of your theory as successes, indulge in self-glorification, and shout down and denigrate anyone and anything that challenges your personal view of yourself and your theory. This isn’t science. It is raw, naked, ugly, disgusting, hateful, ad hominem attacks of the lowest order – in other words – Proof By Volume. Mussolini would be so proud.

As for your demands for my peer reviewed papers all I can say is let’s stay focused on the topic of this thread.  This thread was started by you. It is not about me nor anyone else who has participated. It is about a guy named Fausto Galetto and his pure theory based on axioms and postulates which do not incorporate empirical evidence. Let’s keep it that way.