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Topic Can Six Sigma Tools Be Overkill Sometimes?

Can Six Sigma Tools Be Overkill Sometimes?

Home Forums General Forums Methodology Can Six Sigma Tools Be Overkill Sometimes?

This topic contains 27 replies, has 11 voices, and was last updated by  MBBinWI 4 years ago.

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  • #203577 Reply

    I have noticed that in one of the deployments, where the objective of the project was to reduce Turn Around Time (TAT) of Sev 2 & Sev 3 tickets, a colleague has used tools such as Anderson – Darling normality test, Moods median test, & Mann – Whitney test. While i did not notice any appreciable conclusions derived out of using these tools, i also felt that by using these tools we could potentially be leading toward “tools overkill”. Instead, by understanding Takt & doing a detailed Value Stream Mapping, better results could have been achieved faster. Has anyone faced similar situations? What is / are your views on this? Just because we’re BBs / MBBs, does it mean we have to use these tools even when there is no apparent need?

    #203607 Reply

    @vinay6sigma The potential for “tools overkill” is typically an issue from the way people are taught the Six Sigma methodoogy. If someone teaches you that you must use all the tools on every project then that is what people will do. If the organization puts some ridiculous roadmap in place that defines tool useage this is also another way you get this.

    Now the sequence Normality test, Moods Median test and Mann-Whitney may be an odd combination. I would normally have expected to see a Test of Equal Variances (homgeneity of variance) test after the Normality test. Using Mann- Whitney (2 sample median test) and Moods Median test (2 or more median test) seems redundant. I can’t see why, according to your comment, this would have taken a lot of time. The sample sizes are relatively small and the tests are quick. So how did you decide that this amout of time was longer than a VSM and Takt time calculation?

    Although your question is legitimate here is the problem I have with your example. How do you decide you have the ability to second guess what someone did when they were working a problem? The information this person gained from the hpothesis testing is different that what they would have gained from a VSM and Takt time. Did you ask them why they needed that information from the hypothesis testing or did you jst assume that they did not need it?

    The part where you state “….. i also felt that by using these tools we could potentially be leading toward “tools overkill”. Instead, by understanding Takt & doing a detailed Value Stream Mapping, better results could have been achieved faster.” I assume from your comments you are a BB/MBB. So when did “I felt” become something that was a fact? You also relate the tools to no results. It is very rare that one tool or a series of tests specifically give you a result. I am also puzzled by how you have decided you could have had faster and beter results from YOUR way of doing it. There is only one way to know that and that would be if two of you worked it in parallel.

    I do get fairly tired of people thinking they get much information from Takt time. It is fairly safe to say that there is a distribution around the time it takes to complete a unit. Where in Takt time is there any understanding of the distribution that surrounds the Takt time?

    Back to your question. Is there tool over kill. There can be but it is typically the result of the way the belt was trained, the system they operate within or the quality of the mentoring they receive. Tools answer questions and questions are a function of a person’s thought process. They are the artifacts you have to understand what the belt is thinking. People do things for a reason so without a conversation with a person, the tool selection is pure conjecture. Mentoring from someone who believes they know the one true path to enlightenment and doesn’t understand the thought process is a waste of time for the organization and the belt. It only serves the mentors ego.

    Probably the one thing I find more irritating that a lazy mentor is someone who rolls in at the end of a project and second guesses everything that was done. If a person is truely interested in developing good practitioners gets involved in the process during the process not sitting at the end of the process and acting a some type of judge.

    Just my opinion

    #203621 Reply


    It’s nice you always remind some that takt time changes because as we all known that demand isn’t constant.

    #203623 Reply

    @cseider One of the issues that drove the original Six Sigma metric/philosophy/metrics was calculating averages and using that average as an abolute value to represent a process.

    Lean is basically in the same boat when they do calculations for Takt time, cycle time, etc. They ignore the variation in processes. They discuss times as if it were a single value and they aren’t.

    The general appeal is that the numbers are easier to understand (as if Standard deviation and variance are all that difficult to understand). When you see a process in terms of a discrete value it allows to believe you understand the process when you really have no clue what is happening. As long as you have created the right terminology it does allow people to pontificate ad nauseam.

    Just my opinion.

    #203625 Reply

    @cseider @vinay6sigma I may have misspoken in my first post. I have done a few VSM’s. when I look at how much time they took – not the dressed up computerized version – just on a piece of paper, then I am pretty sure sure I could do the hypothesis test, including data collection faster than I could do the VSM.

    When I first started into this QA/CI world I used to sit in this meetings monthly with another bnch of QA/CI types. Inevitably someone would present a project. It always had a capability study and someone would always raise their hand and say that the underlying distribution was not normal. They did that based on a histogram (long before Minitab was in its current format). Normality may or may not have been true but at the end of the day the person in the audience had no more data, actually probably less, than the person presenting to make that decision about the distribution. After about 12 months of this ritualistic nonsense you get to the point where the question/comment has nothing to do with the project. It is about the person asking the question wanting to appear educated. Generally those are very self serving questions/comments. Particularly if your role is to mentor and grow those people.

    Just my opinion.

    #203633 Reply

    I was doing an executive training class last week and I had just got done mentioning the caution around using averages instead of showing and reporting variation and then started talking about VSM. Someone quickly pointed out that the metrics in the VSM were averages and that I just said to be careful about averages. That was a great point and led to a good discussion about VSM measurements.

    I do think that it is important to know what tools to use and when to use them. That is hard for some new to LSS at first but I think it gets easier as time goes on. What I generally see is that most people get used to a few tools and tend to use them very effectively over time.

    #203821 Reply

    @vinay6sigma I am not sure what your issue is with running a MSA or Capability study. First I don’t care if it is a stop watch for doing VSM’s or whatever measurement system it is you need to know if you are working with good data. I also have no idea how you can do the calculations and not be able to tell if it was repeatability or reproducibility short of someone just not having a clue how to read an ANOVA table.

    Measure is basically setting up a baseline for a problem. If I have a problem I should have a problem statement, that problem statement should involve some type of data that caused someone to believe it was a problem ergo the need for MSA and if I have that data it takes less than 30 seconds to run the capability study. I still don’t see your point. Leave SS out of it. These are just good basic tools to begin solving a problem.

    If the only thing you are getting from Cpk is a decision if a process is centered then you are not qualified to be a BB or a MBB – that is meant to be personal.

    Your comment “But, when there was no measurement on the variance, we felt that this required a relook into the approach & the tools.” That comment makes no sense. You do not measure variance – it is a calculation.

    The is an acronym “MSU” – better known as Making Sh*t Up.” I think that is what you are doing trying to make a point and the only point you have made so far is that you aren’t really qualified to be reviewing projects. Chris is a nice guy – he cares if he hurts your feelings. I don’t. I have been doing this a very long time and it really p*sses me of to see someone like you in a position of power or influence over people who make actually be trying to do something right.

    Do everyone a favor. If you want to be a BB go learn the job.

    Just my opinion.

    #203871 Reply

    @Mike-Carnell – Wow, glad there wasn’t a chair around!

    btw – if you model the VSM in a tool that allows you to add variability (via a MonteCarlo simulation or discrete simulation modeling tool) then you have the ability to understand what is truly happening with the system. Instead of just taking averages which isn’t how any system operates. Just my humble opinion.

    #203895 Reply

    …ah progressions…

    Just my opinion

    Just my humble opinion

    …..and our next posting will be from Uriah Heep…..

    #203897 Reply

    @MBBinWI I am guessing it is way to far to throw a chair although Darth admitted it never actually happened.

    I agree there are ways to integrate data to that it shows the variability. This may be just my narrow view of VSM but once I mix in something like Monte Carlo Simulation it is more modeling than it is VSM. I really liked the earlier comment from the person who said that they had taught SS then Lean and got the questions around averages. That question has been eating at me for years. As we have seen recently if someone wants to produce at some predetermined level and your process is either under engineered or has a lot of down time you have to be able to run really high rates to hit that target as an average.

    @rbutler I am a child of the 60’s and certainly prefered Uriah Heap over disco for the 70’s but you went right over my head.

    #203907 Reply

    The original Uriah Heep was a Dickens villan and his standard line in the novel was ” I am so ‘umble”. We started out with “just my opinion” and went to “just my humble opinion” so I figured the next step in the progression was an application of six sigma to eliminate excess and the next poster would drop “just”, and “my” and go with “‘umble opinion”

    #203927 Reply

    @rbutler I was confused. I thought Dickens took that name from the band. Now I get it. Once they made me do Tale of Two Cities in High School (nobody had written a better book for teenagers to read in the last 100+ years?) I parted company with Charlie Dickens.

    I still like reading you posts. Great stuff.

    #203937 Reply


    It looks like somebody has sc****d you very badly in your working days. That’s why, at your age, instead of donning the role of a mentor, you choose to use abusive language in a professional forum such as this. People like you are a sh**e to the profession of LSS. At least, give due consideration to your age & experience. That way, you’ll do a lot of favour to people genuinely interested to learn LSS. You may be doing a lot of things since ages. So what? It’s no big deal. Unfortunately, age has not taught you to behave in a professional forum. That alone suffices to sum up all that you’ve done in life…Go & get a life for yourself old man. Even now it isn’t late. See if you can do something about it.

    #204001 Reply

    @practitioner That would seem to be a post that was intended to be ironic. Unfortunately it tends to bring to mind Hanlon’s Razor rather than intent:

    Hanlon’s Razor – “Never attribute to malice that which is adequately explained by stupidity.”

    Why is it you nebbishes show up and wrap yourselves in the patina of “profesionalism” to avoid accountability for the completely inane incompetance you post?

    #204089 Reply

    I think more than anyone else, its the expectation from a Black belt that drives a behaviour of using tools. A project deck is perceived as a Power point presenatation with a lot of slides showing minitab and fancy diagrams which on a lot of occasions does not add any value to the project.

    #204095 Reply

    Stoke Prior Andy
    Reputation - 294
    Rank - Aluminum

    There is sometimes a balance when coaching Green Belts to get them to be able to demonstrate their ability to understand and use the tools to gain Accreditation but once that is achieved then it is up to them to use the appropriate tool(s) for the job. Here we insist upon a Project Story Board from them for each Project but even that is only to instil a discipline of telling a story and there are no set rules on which tools they use.

    #204133 Reply

    @Mike-Carnell Who is Practitioner calling an OLD MAN? You are just a young whipper snapper compared to Darth. Glad Stan has bailed on us otherwise Practitioner would be really offended. PS And the only reason I stopped saying you threw a chair at the conference was the recent generous contribution you made to the Don Julio Foundation for the Profoundly Inebriated.

    #204249 Reply

    @Darth Stan still shows up from time to time.

    Practitioner is basically irrelevant. That whole “professionalism” thing is some passive aggresive cloaking device to avoid accountability. We went through it at Motorola with the term “team player” which was basically anyone who didn’t go alon with group think. Never any real definition for it but if someone said someone was not a team player that was it. Pretty idiotic way to work.

    Glad hear that you are a man of conviction. A little Don Julio and then anything goes?

    #204367 Reply

    @talk2manbir Lets take your comment: “A project deck is perceived as a Power point presenatation with a lot of slides showing minitab and fancy diagrams which on a lot of occasions does not add any value to the project.” Who is responsible for that perception? Who is responsible for correcting that perception?

    There is absolutely nothing wrong with a Belt using more tools than required as they work a project particularly if they are learning. We aren’t talkin about large amounts of time. Doing a couple extra hypothesis tests in Minitab will cost you maybe 2 minutes. Worrying about that in the life cycle of a project is minutiae. Someone is picking fly sh*t out of the pepper.

    This is where site support makes the difference in the quality of the BB you train. When you sit down with a belt you need to ask them enough to understand their thought process because SS is about a thought process not a bunch of tools. You should also be able to ask them why they chose not to use other tools – those answers are just as important because getting that thought process instilled in them is what helps them understand the process of choosing tools as they gain experience.

    In terms of the PP deck. Since we began consulting with Allied Signal we have always limited presentations to 10 minutes. Here is the conundrum. Engineers (asuming you are training engineers) by nature tend to want to explain details. Management tends to be predominately high A Low C – they want to dominate and they are impatient. You can allow a belt to make a large deck and wander around in the detail for an hour and you will eventually drive the management people nuts and then regardless of how effective the project is the presentation just marginalized the work. As a MBB/mentor you have the obligation to make a belt an effective presenter. With High A’s you have on the average of 10 minutes before their nature kicks in and they start getting involved in the presentation. You teach a BB that they need to get a story out there in 10 minutes because it is the old adage “know your audience.” If you have put a ton of work into a project and you are asking for money, asking for a change, etc. why would you throw all of that away simply because you or your MBB was so uninvolved they allowe you to run on the perception “a Power point presenatation with a lot of slides showing minitab and fancy diagrams which on a lot of occasions does not add any value to the project.” That is an attempt at being cute and trite but really says I am not doing my job. I don’t think far enough ahead or I am not willing to put in the effort to train my belts well, make them effective and build an effective continuous improvement program because I won’t get involved.

    Your whole post defies logic.

    Just my opinion.

    #204403 Reply

    @talk2manbir – I’d rather that a belt, especially a new one, use more tools than necessary so that they have adequately evaluated the problem. Heck, even a seasoned MBB like me ends up doing analyses that are fruitless – you have to make an hypothesis and then gather some data and see if you’re correct, not, or need more data.

    @Mike-Carnell – so, if I get Darth’s admission correctly, sufficient quantities of alcohol wipe out past actions. Wait a minute, I can’t remember anything before yesterday!

    #204427 Reply

    @MBBinWI @Darth If that is the case then Darth may actually have hit that point where there is no memory at all or at least it is at a point where it can no longer be measured by anything in existence today. He sent me a very nice bottle of Do Julio for my wedding and promised to come down, sit on the porch and drink a while. Almost 2 years (October 22) and he hasn’t shown up yet. Of course he has been chasing a new Mrs. Darth so it may be memory or matrimony.

    #204459 Reply

    “Tools answer questions and questions are a function of a person’s thought process.”
    This statement is an eye-opener for me, Mike: simple but profound. I tend to say that tools are overused/misapplied; and that there is a right way to investigate any process. But your statement forces me to look at the other side of the coin in a different light.
    Thanks for sharing.

    #204489 Reply

    @elaw Eric thank you. remember I typically stick that “Just my opinion at the end.” for a couple reasons first: my attorney says it reduces the risk of being sued; second when it is just what I have experienced and I don’t have data. It has always seemed to work out better for me when we are training and doing site support to focus on how the belt thinks. Besides it is more fun to spend time trying to figure out what they are thinking and how they approach problems.

    Tools by themselves are pretty straight forward. You could teach a cocker spaniel to do this stuff if they had a copy of Minitab.

    Best of luck.

    #204495 Reply

    @Mike-Carnell I beg to differ. I have tried teaching the cocker spaniel and it failed although I got close with a Beagle once. Heck, I couldn’t even teach the second Ex Mrs. Darth but then again….. But I guess I needed the skills of Joel and Jen at Minitab to do it right.

    #204553 Reply

    @Mike-Carnell One of your funniest posts ever. Thanks for the laugh before I head to the balcony with DJ.

    #204629 Reply

    @Darth Thanks.

    I should just let this whole “practitioner” string die but I was just going through some slides from Colin Powell on Leadership and Slide #18 (Lesson 17) struck a familiar note that I thought was worth mentioning.

    “Spare me the grim workaholic or the pompous pretentious “profesional;” I’ll help them find jobs with my competitor.”

    The link to the entire presentation:

    #485995 Reply

    Yes, it may do if we use all of Six Sigma (Design for Six Sigma) tools for every project whether its needs or not. Strategic business consultancy helps to optimize the use of advance methodologies for maximum returns.

    #486099 Reply

    @bmgiindia1 – if you are trying to be ironic, it doesn’t seem to have translated very well.

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