iSixSigma

what is the six sigma?

Six Sigma – iSixSigma Forums Old Forums General what is the six sigma?

Viewing 80 posts - 1 through 80 (of 80 total)
  • Author
    Posts
  • #45628

    smoke
    Member

    Hello anyone;
    I’m a new quality engineer( in fact metallurgical eng.) now my company decidec to send me to a six sigma training.But ý do not anything about also ý have never heard anything about it.Therefore ý do not want to go to training without knowing anything
    could you please tell me about it basicly and simply
    thanks to anyone for your kind attention
    new quality men:)))

    0
    #149519

    Ken Feldman
    Participant

    Well Smokey, let’s keep this simple.  Move your eyes about 2 inches to the left and you will see a link in the blue bar towards the top called “New to Six Sigma?”  Try that for a start.  The other option is to do a Google Search…..wow, what a novel thought.

    0
    #149525

    Ashman
    Member

    Here it is again:
    Six Sigma is a repackaging of TQM carried out as a marketing exercise by Motorola, and later other US consulting firms. Unfortunately the repackaging added a great deal of mis-information. As a result Motorola’s market share fell and they lost 60,000,000 jobs. GE’s introduction of six sigma led to a fall in customer satisfaction that has never recovered. In addition GE turned to outsourcing 70% of it’s manufacturing.
    Other six sigma companies have had similar fate. While Ford and GM are failing, Toyota is about to become America’s number one automaker. This would have been unthinkable 30 years ago. Six Sigma companies lag the S&P 500.
    Six Sigma’s metric is 3.4 defects per million opportunities. This number is based on an assumption that all processes are normally distributed and all processes experience drifting averages of 1.5 sigma. These assumptions are totally false. It is instructive to examine the origins of these false assumptions:

    Bill Smith, a Motorola engineer claims that for uncontrolled processes “batch to batch variation can be as much as +/-1.5 sigma off target.” He gives no references or justification for this. In reality there is no limit to how much that uncontrolled processes may vary.
    At that time Motorola used Cp=1. Bill Smith suggested “Another way to improve yield is to increase the design specification width.” He broadens specification limits to Cp=2.
    Mikel Harry derives +/-1.5 as a theoretical “shift” in the process mean, based on tolerances in stacks of disks. Stacks of disks obviously bear no relation to process.
    Harry names his Z shift. The Z shift makes a number of additional errors: his derivation dispenses with time yet he refers to time periods; he claims a “short term” and “long term” yet data for both are taken over the same time period.
    Harry seems to realise his error in the 1.5 and says it “is not needed”.
    Harry in about 2003 makes a new derivation of 1.5 based on errors in the estimation of sigma from sample standard deviations. For a special case of 30 points, p=.95 he multiplies Chi square factor by 3, subtracts 3 and gets “1.5”. The actual value ranges from 0 to 50+. He calls this a “correction”, not a shift.
    Harry’s partner Reigle Stewart adds a new calculation he calls a “dynamic mean off-set.”: 3 / sqrt( n ) where 3 is the value for control limits and n is the subgroup size. For n=4 he gets “1.5”. Reigle says “This means that the classic Xbar chart can only detect a 1.5 sigma shift (or larger) in the process mean when subgroup size is 4” Reigle is quite incorrect. Such data is readily available from ARL (Average Run Length) plots.
    In summary, the 1.5 does not exist, despite the many attempts to prop it up. Calculations involving 1.5 are hence meaningless. That is, 3.4 dpmo is meaningless. Six sigma tables are meaningless. “Sigma levels” are meaningless.Further reading about the many six sigma fallacies is available at : http://users.bigpond.net.au/SixSigmaFallacies/
    Good quality means “on target with minimum variance”. Forget about six sigma.
     
     
     
     
     
     
     

    0
    #149541

    Saidane
    Participant

    Hi Steve,
    I’m about preparing my first six sigma project, and what you said about six sigma makes me rethinking about my appraoch, is it pessimistic?
    Is Six Sigma a methodology and a management program or a set of statistical tools?
    I want to know others point a view, especially qualitycolorado and Eric.
    thank you,
    Happy new year for all of you,
    Nizar

    0
    #149554

    Mike Carnell
    Participant

    Nizar,
    Six Sigma is not a Methodology. DMAIC is a methodology – basically a rework methodology for something that is in place and was launched at some unacceptable defect level. DFSS or any one of the various knockoffs is a methodology for launching a clean design. As much as people have tried to sell the idea of Six Sigma as a Management System/Program it is not. That isn’t what it was designed to do and it will not do it. It can be used as a part of a management system.
    It can be viewed as a set of statistical tools. It was probably taught to you in that way. It is actually a 5 step process with a different objective for each step. Generally it is taught with a set of tools that fits most problems but is not exclusive of all other tools. If you are at your first project you probably need to stick with what you were taught. If you get to your third project and you are still blindly executing steps then you probably do not understand what you are doing.
    As far as worrying about the 1.5 sigma shift it is irrelevant to the DMAIC methodology. It is this esoteric discussion that consumes some and others just move on to improving their organization. There was an interesting discussion a while ago where the question was posed at what point does the 1.5 sigma shift affect the methodology beyond the Capability Study. Nobody answered that but the answer is that it doesn’t. Nobody has changed any tools such as ANOVA, regression, hypothesis testing, etc. to accomodate the 1.5 sigma shift. The question becomes does an esoteric point completely invalidate a methodology that has been used repeatedly for the past 20 years to move organization forward? For me it does not. You need to make up your own mind.
    The idea that we should be operating to a target is not new thinking. Taguchi put those ideas forward a long time ago. Has the world completely flipped over to the Taguchi way of thinking ? No. Why not? Because for the most part – actually almost universally specification do not have targets – they are specified in an USL and LSL. Many companies require reporting from suppliers in terms of Cpk, Cp, etc and have done that before Six Sigma came into existence so Six Sigma didn’t set anything back 20 years. In general I believe there is an optimal point to operate a process and not being on that target imparts a loss to society just as Taguchi proposed. Believing that there is no intermediate step between where you are now and operating everything to a target is like the person who quits smoking and goes on a diet at the same time. There is a low probability of success. We don’t even need to discuss how it will completely piss off your customers to have you report Cpm/Cpt when they want Cpk. Quality does have something to do with customer satisfaction. Reporting your data in a format that they are not interested in leaves a pretty big gap in the customer staisfaction arena.
    Just my opinion.
    Good luck

    0
    #149555

    BritW
    Participant

    Nizar:
    Six Sigma is a methodology, not a set of tools.  The functional implementation requires more than just reading a book and learning some tools. There have been successes and failures with Six Sigma as well as other methodologies.  I doubt that the successes were entirely about Six Sigma, as I doubt the failures were entirely about six sigma.
    I would warn against taking only a one sided opinion from people who obviously have had a bad experience with a particular quality methodology.  There is good and bad in all of them, especialy if they are not implemented as suggested.
    Yes – Steve’s message was pessimistic.  There are others as well.  You will find a lot of information out there on the reasons why six sigma (and teaming for that matter) fails.  I suggest taking those ideas to heart as you move forward with your project so it can be a success.

    0
    #149558

    BritW
    Participant

    Nizar:
    It may seem from mt post that myself and Mike are at odds with what we said.  We are not.  I agree that DMAIC is the methodology and the measure of six sigma by itself is not.  When I mentioned “Six Sigma” as a methodology, I was referring to the body of implementation (leadership, change menagement, project selection, DMAIC/teaming, implementation, et. al.) and not the measure of six sigma itself.
    Hope I haven’t confused you – best of luck

    0
    #149559

    BritW
    Participant

    Mike – your statement:
    “As far as worrying about the 1.5 sigma shift it is irrelevant to the DMAIC methodology. It is this esoteric discussion that consumes some and others just move on to improving their organization. There was an interesting discussion a while ago where the question was posed at what point does the 1.5 sigma shift affect the methodology beyond the Capability Study. Nobody answered that but the answer is that it doesn’t. Nobody has changed any tools such as ANOVA, regression, hypothesis testing, etc. to accomodate the 1.5 sigma shift. The question becomes does an esoteric point completely invalidate a methodology that has been used repeatedly for the past 20 years to move organization forward? For me it does not. You need to make up your own mind.”
    Nice – probably the best answer to the constant 1.5 naggers I have seen.  I should be posted on the front page of the website…

    0
    #149560

    Marlon Brando
    Participant

    Agree.
    I  would  add  “SS is  a  management Philosophy” if  you  agree?

    0
    #149561

    Marlon Brando
    Participant

    Snee (1999) provides some reasons  why  SS works:
    *Bottom line results
    *Senior  management  is  involved
    *A disciplined approach is  used (DMAIC)
    *sHORT  PROJECT  COMLETION TIMES  (3-6 Months)
    *Clearly  defined  measures  of  success
    *Infrastructure of  trained  indviduals
    *Customers  and  processes are  the  focus
    *A sound  statistical approach is  used
    Now  if  SS failed in  Implementaion (in some  cases),then  it  is  the resposibility of  those who implement  it  wrongly,not  the  SS itself?

    0
    #149562

    Mike Carnell
    Participant

    BritW,
    Thank you. I have never particularly cared one way or the other about the issue. I am constantly amazed at the amount of energy that is put into the issue.
    At the end of the day we touch on it when we train simly because it is something a MBB/BB/GB needs to be aware of. We prefer hard data.
    I hope you are having a great holiday season.
    Regards

    0
    #149563

    Mike Carnell
    Participant

    How is it a management philosophy?

    0
    #149564

    Marlon Brando
    Participant

    A business comprehensive improvement  approach that  seeks to  find and  eliminate causes of  mistakes or  defects in  business processes by  focusing on outputs that are of  critical  importance  to customes.
    Thanks  for  the  enlightenment?

    0
    #149565

    BritW
    Participant

    I think the philosophy would be the elimination (or near elimination) of defects via a structured teaming approach/methodology.  I think I would classify the DMAIC steps as a methodology toward that philosophy.  There are other methodologies that could be used as well to reach that end. 

    0
    #149566

    Mike Carnell
    Participant

    “A business comprehensive improvement” One of the major issues that show up in deployments that are under-performing, is that it is not applied to a business type problems. Six Sigma on it’s own would be a poor approach to improving a business. It may be part of the solution.
    “…by  focusing on outputs that are of  critical  importance  to customes.” More often than not Six Sigma is applied to cost reductions which in most cases has nothing to do with the customer. Check out the blog site and read the piece by Mike Cyger on pet peeves.
    The DMAIC and DFSS methodologies are somewhat understood to be certain things and encompass certain tools. When you try to extrapolate it beyond the methodologies it becomes more of how does it support a larger strategy. Some of what you have in your elevator speech is probably true but it isn’t a function of Six Sigma as much as it is a personal strategy that will use DMAIC and DFSS to accomplish it.
    This is probably more of a chicken and egg type discussion with nobody really moving very much.
    Just my opinion.
    Regards

    0
    #149567

    Six Sigma Shooter
    Member

    Might the philosophy be one of continual improvement with the reduction of variation and defects as one of the objectives?  Other objectives would be the improvement of the culture and business systems that support the philosophy of continual improvement.  Six Sigma, Lean, etc provide certain tools and methods to help in achieving the objectives within the framework of the philosphy?
    Just my opinion,
    Shooter

    0
    #149568

    BritW
    Participant

    Sounds good to me…

    0
    #149570

    Craig
    Participant

    Steve,
    I think your quote below is an example of extreme misinformation. It also seems a little biased. Do you honestly think that Motorola lost market share and 60 million jobs because of Six Sigma? I assume you meant 60 thousand jobs, not 60 million, but heck…its only 3 extra zeros!  It is real challenging to establish real cause & effect in everyday life. Common mistakes (Just like your quote below) occur all the time where correlation is observed, and cause & effect is automatically assumed.
    From my EXPERIENCE working at Motorola, I saw the following issues that lead to loss of market share, outsourcing, etc. These are just my observations.
    Motorola did not put enough resources into the digital cell phone market at the right time. Analog became a thing of the past, and Motorola had to play catch-up. If we could have been more aggressive in the digital market, things would have been very different.
    Management philosophy changed regarding manufacturing. When I joined the company in the mid 80s, manufacturing was seen as a core competency. We manufactured everything we could throughout the entire supply chain. In the 90s I heard a General Manager challenge his team to come up with a reason why we should continue to manufacture internally when we can buy the products from outside sources. Guess what happened? Even though our quality was superior to the foreign competition (thanks to the correct application of Six Sigma), even though our costs were the same, we were not going to win the argument. Sadly enough, the whole division was shut down.
    Motorola invested heavily into projects (Like Iridium), which resulted in huge financial losses. The fact that they never came to fruition was an example of poor market research, not Six Sigma.
    Steves quote. A perfect example of erroneous cause & effect analysis.
    “Six Sigma is a repackaging of TQM carried out as a marketing exercise by Motorola, and later other US consulting firms. Unfortunately the repackaging added a great deal of mis-information. As a result Motorola’s market share fell and they lost 60,000,000 jobs. GE’s introduction of six sigma led to a fall in customer satisfaction that has never recovered. In addition GE turned to outsourcing 70% of it’s manufacturing. “

    0
    #149574

    Fontanilla
    Participant

    Elimination of defects is nonsense because defects relate to the specification. As the founder of six sigma, Bill Smith said :

    “Another way to improve yield is to increase the design specification width. This influences the quality of the product as much as the control of process variation does.” (page 46)
    You can set whatever defect level you like by using the great Mr Smith’s method !!

    0
    #149579

    Mike Carnell
    Participant

    Dan,
    That is a ridiculous comment. First if you are supplying something to a customer for the most part the customer controls the specification. If you believe that it is that easy to change a spec – work as a supplier to an automotive OEM and change the spec to adjust your defect rate.
    If your product is specified correctly – the product performance is affected when outside the specification – then you cannot adjust a specification because you are affecting the performance of the prouct.
    You have taken an extreme interpretation and are making your position look ridiculous with your interpretation.
    Just my opinion.

    0
    #149582

    Craig
    Participant

    Hey Mike,
    I can just see Dan at the McDonalds counter.
    Cashier: Sorry sir, but we have an internal spec that requires our hamburgers to be round within .050 inches. The last batch was at .055, so we have to scrap it and you will have to wait 20 minutes for the next batch.
    Dan: I really don’t care if the burger is a little out of round. It makes no difference to me. Geez, I even had a square one at Wendy’s yesterday! Why don’t you relax that ridiculous spec?
    Cashier: Even though we have specifications that make no sense, we are not allowed to change them. Please pardon our ingorance and wait twenty minutes for the next batch.
    Dan: Well, I just slammed Bill Smith on ISixSigma.com about the concept of widening specifications to reduce waste, so I suppose I should not be hypocritcal and just wait for my perfect burger.
     

    0
    #149583

    Mike Carnell
    Participant

    hacl,
    They seem to have a couple of concepts confused. The customer spec is typically a window where the product is functional. There is usually a spot that is optimal for the manufacturer.
    If you consider plating a precious metal such as gold. The spec is typically an USL and an LSL. The obvious economic target for the manufacturer is the LSL with a std deviation of zero. If I do not have a std dev of zero where is the target?
    Can you imagine the people we built PCB’s for if we did the McDonalds scenario with them “sorry the boards are within your spec but they are off target. We won’t be delivering anything again today.” This is where we are getting caught between some esoteric concept and what happens in reality. If we only deliver what is on target we have to have a process with no variation. Nothing in between either on target or scrap. PWF would still be trying to deliver its first board.
    I hope you and your family had a very Merry Christmas and have a safe, prosperous and happy New Year.
    Regards

    0
    #149586

    Saidane
    Participant

    Hi Mike,
    How are you?
    thank you so much for your time and consideration.
    Certainly, you provided me with many interesting information. I’ll tke more time to analyze it, I’ll reply to you soon.
    Good luck, and Have a nice time,
    Happy new year,
    Nizar

    0
    #149587

    Saidane
    Participant

    Hi BritW,
    Thank you for your time and consideration.
    I totally agree, Six Sigma is a methodology. Its success or failure are closely linked to how the DMAIC process is adapted with  the specifications and requirements of the organization.
    thank you again,
    Have a nice time, Happy new year!
    Best regards,
    Nizar

    0
    #149604

    Ropp
    Participant

    Steve,
          Why do you spend so much time on this site when all you do is put ss down, please amaze me and say you have worked with Toyota, i have and someone like you would be shown the way out!!!!!

    0
    #149606

    Bob K
    Participant

    …..see what you started

    0
    #149611

    Tierradentro
    Participant

    Dave,
    Since you’ve worked for Toyota, could you please explain how they determine standard times?
    Cheers,
    John
     

    0
    #149616

    Cravens
    Participant

    Wakey wakey Mike –  Dan is simply quoting your hero, Bill Smith !!!!

    0
    #149622

    Ashman
    Member

    Yes, Motorola sacked 60,000 !!!
    Mass sackings, loss of customer satisfaction, loss of market share, falling share prices are all signs of business malaise, endemic in six sigma companies.  As Deming pointed out, and as is evident in Toyota’s success, quality is an approach to business, not just individual projects.

    0
    #149624

    Craig
    Participant

    Steve,
    Thanks for the clarification. Sacking 60 million jobs sounds a bit large. I suggest you take a regression class so you can add a few more X’s into your equation. Six sigma company (yes versus no) sounds like a limited and biased view point. You are so mis-informed it is pathetic, and I hope the other readers recognize your bias.
    I spent 15 years with Motorola in an intense quality culture. Please elaborate on how Toyota takes a quality approach to business.

    0
    #149627

    Mike Carnell
    Participant

    Wakey wakey Fred. It doesn’t matter who said what, the fact is specs aren’t all that easy to move. So rather than continuing to make stupid statements lets talk about how the world works rather than how you want to twist things around to make some point that doesn’t mean s__t.
    You determined Bill Smith was my hero how?

    0
    #149691

    Tierradentro
    Participant

    Dave,
    Please respond to my previous request. How does Toyota determine a standard time?
    If you don’t provide the answer you’re only lending support to the view this forum has now become the BS forum.
    John

    0
    #149693

    Six Sigma Shooter
    Member

    Not sure, but I think they would set their standard time by using a watch, if they do it at all.  They’d probably do the same for setting their daylight savings time, too, I would imagine.  Sorry, I just couldn’t resist . . .  Wishing you a great New Years!

    0
    #149694

    Ropp
    Participant

    John,
       TPS views value as a combination of cost,quality, and time. Cost is the total expense involved in the delivery of the product. Quality is any deviation from the standard. Time is best captured as the total elapsed process time from the start of a part, or transaction to its delivery.
     
     Regards,
     
     Haz

    0
    #149697

    Mikel
    Member

    John,It is idiotic statements like “If you don’t answer” that threaten to turn this into a BS forum. Who are you to make such a statement?If you want to know what Toyota or any other truely lean org does, go learn about takt times.

    0
    #149700

    Mike Carnell
    Participant

    John,
    I am with Stan on this. Why would you believe you have the clout to define the forum as BS because someone doesn’t respond to your question? If you had any idea of the size of the readership of this forum you would realize you are way out of line.
    There is a book by Monden from Toyota that should give you all the insight you need into the Toyota system.
    Just my opinion.
    Good luck.

    0
    #149704

    Tierradentro
    Participant

    Haz/Dave,
    Your reply is complete rubbish, which just goes to show how many BS’ers post messages on this forum.
    Standard times are not measured- they are calculated!!!!!
    John
    (Toyota UK)

    0
    #149705

    Tierradentro
    Participant

    Really, I don’t need to read a book because unlike you I’ve actually done it!!!

    0
    #149706

    Ropp
    Participant

    John,
       Why are you talking like this, i did not know how they CALCULATED it so i looked it up on a web page, i was a supplier quality engineer working with Toyota, i would not have been involved in this process, i also had a lot of respect from the guys i worked with there.
     I do not talk BS.
     
     Regards,
     
     Dave

    0
    #149707

    Six Sigma Shooter
    Member

    John,
    Come down off your high horse, my friend.  Toyota has its problems, too.  Once heard a guy from Toyota at the NUMMI plant in Fremont say that we must “decorate the data because it is not good for management’s health if they get upset.”  When asked if he was saying that we should lie about it, he said no, just not tell them the truth.  Nice spin on it by calling it “decorating the data.”   Go figure.

    0
    #149708

    Cravens
    Participant

    Now now Mikey, no need to get angry and start swearing … it’s supposed to be the happy season you know. Perhaps you also don’t know that Bill Smith is the daddy of your SS rubbish.

    0
    #149709

    Mike Carnell
    Participant

    Fred,
    I do appreciate your concern over my getting angry unfortunately it will take someone with a little more intelligence than the nonsense you post to irritate me. Your living in the past. I have no issue with Bill Smith as the father of Six Sigma but you comment is he was my hero. That was based on?
    Try putting up something besides your glittering generalizations.

    0
    #149710

    Mike Carnell
    Participant

    Since you have “actually done it” why did you ask the question to begin with?

    0
    #149713

    Cravens
    Participant

    Mikey,
    Good to see that you have calmed down.
    Bill Smith, the big daddy of six sigma, make the earth shaking statemnent that quality can be improved by widning specification limits and that this was just as effective as reducing variation.
    Is that glitteringly specifc enough for you ?

    0
    #149718

    Marlon Brando
    Participant

    Several  operators (world-wide) are  doing  the  same:decorating  the  data,just  to  show  that  everthing  is  normal?

    0
    #149720

    Six Sigma Shooter
    Member

    Yes, everything is normal in the organizations you refer to.  Fear runs rampant and people lie and fudge the numbers to survive when fear runs rampant.  Ain’t it sad that people have to work in such places?

    0
    #149734

    Tierradentro
    Participant

    Clearly, a supplier quality engineer does not ‘work for Toyota’ as you claimed. A similar claim had been made previously by another supplier in India, which is why your post was brought to my attention.
    Not that it is a problem in itself – the problem was your use of a deception to put someone else down, which is why I decided to set a trap.
    I’ll leave others to draw their own conclusions.

    0
    #149737

    Ropp
    Participant

    John,
     My post read”please amaze me and say you worked WITH Toyota, i have”
    Learn to speak with data
    I too will let the others draw their conclusions on you
    so what is your function at Toyota, i will then ask a few of my Toyota mates whats wrong in your life.
     
     

    0
    #149738

    Ropp
    Participant

    John,
        what are your views on kami-shabai

    0
    #149739

    Mike Carnell
    Participant

    Wow Fred you have a 20+ year old quote from a person who is no longer with us. What a devastating piece of data – if you are an avid fan of the National Enquirer.
    If that is all you have maybe you need to look over to the “New to Six Sigma” in the blue column on your left and see if you can tackle something with a little more substance.

    0
    #149741

    Larry
    Participant

    I am still in the dark. What are  the advantages of Six Sigma ?

    0
    #149743

    Cravens
    Participant

    Mikey,
    So you are saying that we should not use any of the priciples of sick sigma as laid down by Bill Smith ?  We should not use six sigma tables, and changing to Cp of 2 ? 
    Yes, it is very old now and most people and I do agree that most of what he said was total crap.

    0
    #149764

    J D
    Participant

    There are none.  It is a retrograde step.

    0
    #149765

    Mike Carnell
    Participant

    I have no idea what sick sigma is and I do not believe Bill Smith had anything to do with something called sick sigma.
    You are another one of those people who is chosing to try to make some issue out of the 1.5 sigma shift.  The interesting part is that you can’t seem to get past it and you seem to think it has some effect on what is going on today. It doesn’t. The methodology has evolved and you seem to driving forward staring in you rear view mirror.
    As far as what is total crap – that would be primarily driven by people such as yourself that can’t seem to find any relevant issues. Try one of the scandal rags they seem to more into the he said/she said stuff you favor as opposed to anything of substance.

    0
    #149770

    Chris Seider
    Participant

    Fred,
    You have been dismissive with your comments about the six sigma methodology.  I wish you would contribute why you are so taken aback.  That would be more interesting that using one or two syllable words to describe six sigma.
    Let me add another voice of reason.  You have taken a quotation from Bill Smith and ridicule it as an example of *&^%.  Maybe you could consider he was explaining the concept of potential capability which many have difficulty understanding.  Have you never used such a ridiculous example that would be stupid to discuss with an experienced person but it helped bridge the gap of understanding.  Harken back to the days when we had to learn about how many hours before two trains leaving Boston and New York would meet if only traveling 60 mph.  It would be stupid to discuss this with Amtrak but I’m sure it’s eye opening to those new to word problems relating to mathematical equations.
    From one of those who believe with an unshakeable faith.

    0
    #149771

    Cravens
    Participant

    “You have taken a quotation from Bill Smith and ridicule it as an example of *&^%.  Maybe you could consider he was explaining the concept of potential capability which many have difficulty understanding.  “
    There seems to be a lot of anger here !!
    Let’s have a look at Bill Smith’s statement :  “Another way to improve yield is to increase the design specification width. This influences the quality of the product as much as the control of variation does.”
    Smith makes no mention of “potential capability” as you suggest.  This is one of the most fundamental flaws of six sigma … it is a methodology based on specifications.  You can get any level of defects you want, simply by changing specs as Bill Smith suggests. 
    World class quality can only be on target with minimum variance. 
    Forget Mikel Harry, Bill Smith and their nonsense.  Read Shewhart and Deming.
     
     

    0
    #149773

    Mike Carnell
    Participant

    “There seems to be a lot of anger here !!”
    You like to write everyone off as being angry and the truth of the matter is you aren’t intelligent enough – at least in your posts – to make anyone angry.
    As far as your stay ontarget with minimum variation. Nice esoteric line. Nobody has an issue that that is a good thing. Lets look at what Deming says about quality by exhortation.
    “Minimum variation” define it.

    0
    #149775

    Chris Seider
    Participant

    Evening Fred,
    Yes, I only got frustrated seeing a continuing string of derogatory comments about something I care about but not angry!  Your last post was interesting since it started to give more insight to what you are driving towards.
    Oh by the way, I’ll try and delve into what you are philosophizing against.  Process specs do help define defect levels as you have stated and that is the focus of six sigma results to reduce defect levels.  I appreciate Taguchi’s loss function but I have not been satisfied with knowing how to describe it beyond theoretically the symmetric parabola.  The math is more difficult but I’m sure it could be translated to a % loss or defect level.  OK so I grant this.  I don’t think there is much difference in goals from what I and others are doing with Six Sigma and what Deming, et al are trying to do with their past teachings.  If they are contradictory, let me know since I have not gathered this.  If they are different but in the same general direction, will you grant this?  Specification levels even define quality for Crosby and the Taguchi losses so I’m not sure why you are focusing on the specifications. 
    In the spirit of Crosby, my comments are “free”. 

    0
    #149779

    Cravens
    Participant

    Quite importantly, Taguchi’s Loss Function is not a “symmetric parabola”.  It is a function of arbitrary shape with some minimum.  It  leads directly to the proposition that good quality is on target with minimum variance. 
    The Loss Function does not relate to “defect levels”.  Defects relate only to specifications.  Spec levels are independent of process behaviour.
    Six sigma is very much at odds with Taguchi.  Six sigma is based on counting defects, that is, it is a specification based methodology.  Defects levels say nothing about the process or the quality of a product.  Defect levels represent a step function where some arbitrary decison is made to say that the product is “OK” at one point and “not OK” at the next.  This is very similar to the old days of quality assurance. 

    0
    #149783

    Mikel
    Member

    I agree with most of what you say except you should take your own advice and really read what Bill Smith said. In that you are hanging on to a snipet taken out of context tells me you really haven’t read what he wrote.
    I agree about Taguchi and minimizing variation to a target and also agree it is not necessarily symetric. Putting ideas like this into action is where the problems are. We still live in a “it meets spec world”. Six Sigma didn’t do this and like Taguchi is very much at odds with it. You can have a Cp of 2 and Cpk of 1.5 (the real definition of Six Sigma if you go do your homework) and still not be on target. That is a problem only occasionally since target is geneerally the center of a two sided spec. But I will grant it can be a problem.
    Whoever taught you that Six Sigma is a defects based method didn’t know what they were talking about. Go ask for your money back.
    I do agree also that the stuff from Harry isn’t worth the paper it is written on (or the hard drive space it occupies).

    0
    #149787

    Marlon Brando
    Participant

    Bottom line  results/A disciplined  approach (DMAIC)/Short  project  completion//Infrastructure of  trained  individuals(GB,BB..)/Asound  statistical  approach….

    0
    #149793

    Mike Carnell
    Participant

    Stan,
    Nobody has an issue with the idea of operating to a target but Fred’s little tantrums over specifications is somewhere beyond stupidity. It lacks any relevance in how a person has to operate when they are involved with a customer.
    Think back to the element factory. We are sputtering gold between 900 and 1200 angstroms – the specification from the customer (for Freds benefit that is how customers communicate with suppliers so the supplier knows what they want). The logical target for us is 900 – it satisfies the customer and it is the lowest cost position for me to run the process. The problem to run at 900 is that my standard deviation has to be zero. It wasn’t so where do we put the target and how do you determine the target? With SS I can move off of 900 six standard deviations and understand the risk my customer is at. As I reduce the variation I can move closer to 900.
    Was I motivated to operate at 900? Of course. When a VP stands in the door of your office and says “Carnell for what I scrap in gold every day I can drive a f–king Lincoln Continental off a bridge every day.” you are motivated to run at a minimum target and minimize variation. Even that VP understood you do not put the customer at risk.
    Fred doesn’t get this part. This is where this “operate to a target or you are setting quality back 20 years” nonsense does nothing more than demonstrate he spends a lot of time buried in books and does not have any practical experience.
    This ranting about on target and minimize the variation is about as ignorant. Talk about setting the industry back 20 years. That is back to placing the mean on the target. Minimize variation – what does that mean? At least with Six Sigma I know that if I am running a process centered then the target standard deviation is the spec divided by 12. If it is off center than it is the distance to the closest spect divided by 6. There is nothing in six sigma that precludes me from setting a target.  I know I am going to provide my customer with some level of protection assuming he has speced his product correctly. To just lay out the “minimize variation” like a turd in a punch bowl doesn’t provide any intelligent direction. That goofy bunch that ran the element factory before we got there believed it was optimized when the yield fluctuated between 7% and 60%. Let’s have Ruta and company define a minimized variation for the industry.
    Lets go back to the element example and you picture yourself in another one of those interesting Ford meetings tell our friend Jim “don’t worry about your elements. I know your spec is 900-1200 but we have a target of 900  and we are on that target. We have minimized the variation and our standard deviation is 500 angstroms but we aren’t worried about the target, spec and variation because then we will be setting quality back 20 years. It is much better to speak very avant guard and ship junk.” Our buddy Jim would be back on his feet screaming as usual with the viens in his throat sticking out.
    Tell me about dinner with Marty some time.
    Regards

    0
    #149798

    Mikel
    Member

    I, of course, agree.
    I am trying to get these guys with their out of context quotes from Bill Smith into a different discussion.
    I know that you know the ideas of Six Sigma and Taguchi are not at odds with one another.
    I’ll send a note about Marty later this week.

    0
    #149800

    Mike Carnell
    Participant

    It was a rhetorical question. A verylong rhetorical but it was nice finally have someone besides Chris and I in this discussion that wasn’t off on some esoteric rant believing that they had found something that had made Six Sigma irrelevant.
    The stuff with the Bill Smith quote is stupidity that Fred self servingly likes to interpret as anger. That would be akin to getting angry with a rock – you can’t get angry with a rock because it has no intelligence.
    Regards

    0
    #149805

    systhinc
    Member

    Fred”s comments are not stupid.  Angry, yes, but not stupid.  Much of the Motorala method is statistically incorrect.  The mean shift question tis of great importance.  The question of spefications, dimensions and tolerancing is of great importance.  Most of you new “six sigma professionals” have no quality background and do not understand the importance of these issues.  Please understand, the methodology is of no value without an understanding of the underlying issues, which I think you do not have.

    0
    #149806

    Mike Carnell
    Participant

    The mean shift is irrelevant in what is delivered today.
    I am a long way from new to this.

    0
    #149807

    Mikel
    Member

    Oh systhinc, please tell us of your superior background. I think you are a light weight and don’t have the background you are inferring.
    Other than the 1.5 nonsense and the associated tables, what of Motorola’s method is incorrect?

    0
    #149808

    systhinc
    Member

    Semantic point well taken.  The point is continuous improvement.  There’s nothing wrong with Motorola’s method other than the mean shift question, and that, only because it assumes uncontrollable variation.  Sorry to have sounded anti-Motorola.  I am not.

    0
    #149809

    Mikel
    Member

    Thank you – I agree
     

    0
    #149825

    Cravens
    Participant

    I have read what Bill Smith said and I have his paper in front of me right now. My quote is not taken out of context.  Smith goes on to give an example of widening spec limits to reduce defects.
    You have a fair understanding of Taguchi but putting it into action is easy if you follow it’s full derivation.
    Virtually every SS site on the net claims “the metric for SS is 3.4 dpmo” … check them for yourself … it certainly is a defect based methodology !!!

    0
    #149826

    Cravens
    Participant

    Stan,
    “Whoever taught you that Six Sigma is a defects based method didn’t know what they were talking about. “
    You are wrong … you can even check this isixsigma site https://www.isixsigma.com/dictionary/Six_Sigma-85.htm
    “Metric: 3.4 Defects Per Million Opportunities.”
    But I will agree with you … they are don’t know what they are talking about …
     
     

    0
    #149827

    Chris Seider
    Participant

    Fred,
    One must remember words have many connotations.  When I referred to defect reduction being the focus of Six Sigma, I define, in common company, that defects are additional work to produce value and can include waste, or waiting, cycle time, rework, etc.

    0
    #149834

    Cravens
    Participant

    Mikey,
    I really seem to have upset you haven’t I !?  There you are sputtering gold … I hope it’s not coming from those loose gold fillings in your molars.  I can just picture it … stammering and sputtering with drool running down your chin.
    Perhaps someone might like to explain to Mikey what reducing variation is all about.  Even Bill Smith talked about it 20 years ago.

    0
    #149862

    BritW
    Participant

    Fred: from Dan’s post…
    “Another way to improve yield is to increase the design specification width. This influences the quality of the product as much as the control of process variation does.” (page 46)
    Not sure if he was advocating the improvement of the process by widening specifications, just that the effect on the count of defects will chnage.  The effect is that you will have less defects if the design specs are widened.  Now – whether the customer will accept those specs is another story – of which he was not referring.  Design specs and customer specs aren’t always the same thing – especially in a fluctuating market.
    Making the leap that all we need to do (or that Smith was advocating) is to widen specs and we all look better, sell more, and make more money, is rediculous.

    0
    #149885

    Ropp
    Participant

    Come on John,
                        I take it the fact you have read what i wrote first, i worked with Toyota, if i was you, i would walk the green mile and not show my silly little self on this web page again, well, what department do you work in, what do you think about kami-shabai, or are you walking around the Burnaston plant asking people who know Toyota, you see, i’m even giving you the chance to tell every one you have worked there for a number of years.
    Remenber big mouth, speak with data, i had a go at someone on the web who attacked me when i was asking for help on my second post.
     
     Dave
     

    0
    #149888

    Hal
    Participant

    BritW,
    “Making the leap that all we need to do (or that Smith was advocating) is to widen specs and we all look better, sell more, and make more money, is rediculous.”
    Good to see that you have realized the stupidity of six sigma !!!!!!!!!!!!

    0
    #149891

    BritW
    Participant

    Hal,
    You really missed the point – I thought you had more smarts than that. 
    The point is that moving specs gives you “improved results” on paper.  If the customer isn’t willing to pay for the worsening product, then the results are frivolous.  It is all about the customer – which is what SS is all about.  What he said was true – there are two ways to make results look better – improve the process or widen the specs.  Widening the specs on a “whim” is rediculous and is not what is advocated by six sigma (or any other improvement process).  So, no, I don’t think SS is stupid – it has worked very well for me.

    0
    #149893

    Mikel
    Member

    I can only see the stupidity of Hal

    0
    #149908

    Dan O’Conner
    Participant

    I agree.  Specs should not be widened on a whim.  They should only be widened to improve quality as part of a project run by a black belt.  This way six sigma quality can always be guaranteed.

    0
    #149936

    Mike Carnell
    Participant

    Back with the upset stuff again. For some reason you seem to believe you have the ability to upset people. As much as this may disappoint you you don’t. Chris Seider is about as even tempered as they come and you still had that same stupid resonse to his post. You don’t seem to get it – you are the one looking angry and even more importantly you are looking pretty stupid.
    Here is the difference Fred. First you have no idea what a sputtering process is. Second, in your typical fashion you want to rattle off more dogma and won’t answer a question in all probability because you can’t.
    Stick to the esoteric. You’ll never have to actually do anything and you can always duck and dive when you get caught by someone with application experience. 

    0
Viewing 80 posts - 1 through 80 (of 80 total)

The forum ‘General’ is closed to new topics and replies.