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How to reduce subjectivity in Six Sigma

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  • #37273

    Neel Vaidya
    Participant

    Hi, I’m a college student doing some research on Six Sigma and I’m wondering if anybody out there can tell me some ways to reduce the amount of subjectivity used in the Six Sigma approach and how you may have encountered this on the job?
    I hope you will entertain the “fool” questions of a dumb kid..hehe…

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    #109392

    Sharma
    Participant

    Hi Neel,
    Actually it is a good question.
    Six Sigma is a highly objective concept. Many tools used in Six Sigma like QFD, FMEA have however, some amount of subjectitvity as for instance scores/ratings are mostly judgemental (human assigned) values. Most of the other tools have statistical drive like Process Capability, Anova, DOE, control charts  etc.  Further most of the applications of Six Sigma in manufacturing have objective basis as there are robust measurement systems in a manufacturing environment but some amount of subjectivity may be encountered when Six Sigma is applied in transactional areas where the numerical data at times is not measured and do not exist, for instance, say  in case of a measuring marketing effectiveness, customer prefernce or knowledge transfer  
    In orderto reduce this something like R&R concept needs to be adopted where a sizable number of judgements/ opinions (from different sources) are taken into account. Also it is better to define practical ratings and scales to convert objectivity to subjectivity. 
     

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    #109398

    RubberDude
    Member

    Neel,
    Take a look at some of the posts in this forum and you will see your question is certainly not “fool” at all.  Yours is one that will cause a few of us to really think…..
    As for my response, I am of the opinion (and we ALL have one) that there should be a certain amount of subjectivity allowed in the front end of any problem solving project.  We have always been challenged to “think outside the box” in these situations.  Therefore, subjectivity CAN have value, especially in the brainstorming part of a project.  As long as you keep the open-mindedness and free-thinking in this phase, then “burn out the chaff” as you go further into the project.
    Keeping the subjectivity out of the other end of the project is difficult.  Just keep in mind the idea of facts backed up with data backed up with facts backed up with data backed up with facts backed up with data…… etc.  R & R is a must.  This is also why SS and other problem solving/improvement systems must be a true team approach.  This tends to keep you from leaving a stone unturned or a door open in your end results.
    Just my opinion…..
    RubberDude – Certified Grand Master Holiday Inn Express Black Belt

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    #109405

    OLD
    Participant

    Neel:
    You have received some excellent feedback from Abhishek and RD. I would add:
     
    Subjectivity should play a role in project selection – based on the needs/priorities of the organization. With our projects we have tried to balance payback with VOC/internal urgency. Subjectivity has also entered into our GB training as we are always attempting to give our GB’s enough skills to be successful without wasting time/overkill (we have developed specialized training for GB’s based on the needs of their particular projects).
     
    As far as reducing subjectivity in SS goes, I think it is helpful for all SS companies to develop/publish/follow their SS process standards. Examples include (but not limited to):
    1). Project selection criteria
    2). BB/GB Training Standards (minimum requirements)
    3). Responsibilities of all the SS roles (including leadership/management)
    4). Project accountability and follow-up to ensure DMAIC and DFSS is followed
    5). Compensation for the SS roles
    6). Progression/Succession plans (GB’s to BB’s to MBB’s to Mgrs., etc.) 
    The early adopters/pioneers (Motorola, Allied Signal, GE, etc.) have helped to define the standards for most, if not all of the SS process. Following those standards will help eliminate subjectivity that comes into play when companies try to take easier, less disciplined paths….
    Good Luck!  OLD

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    #109627

    Deanb
    Participant

    Neel,
    I consider the goal of higher thinking not to be one of replacing subjectivitity with objectivity, but to improve the quality of both, especially since both are essential to problem solving. Issues such as value rankings, who ought to win and who ought to lose, what the greater good outcome ought to be, behavioral effects, unintended consequenses, stakeholder issues, all are more ethical in nature than scientific, however both are absolutely essential to human rationality and effective decision making.
    The Nobel laurate economist and decision scientist Herbert Simon wrote “the most important part of solving any problem was identifying  the nature of the problem at the beginning from perspectives of both value and fact.” [Rational Decision Making Under Uncertainity]. Many great scientists, ethicists and philosophers down the ages have shown time and again that without well reasoned values working with science, the effectiveness of the scientific approach declines precipitously.
    Problem solving is both art and science, and always will be. Just read this board for an hour and you will find considerable differences between master black belts on just about any approach to any kind of problem. Some of the differences are technical in nature. Many differences however reflect differences in subjective judgements. Who’s most right usually depends on who forwards the highest quality combination of “objective” and “subjective” ideas. 
    Good luck. 
      

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    #109690

    Neel Vaidya
    Participant

    Thanks for your reply.  I initially proposed this question was after I was asked this by my professor.  At that time I just took it as a given, based of his cue in that question, that too much subjectivity when using six sigma was a bad thing.  Now as I have done some more research on the topic, I am beginning to realize that it is not so bad and as stated in the post by DeanB, it is necessary to combine the objectivity and the subjectivity together in order to solve the problem.  In fact as I have continued reading about process quality I have started to really appreciate the subjective nature of the quality control process.  One source I read about raved on and on about the pros of ISO 9000 and that it is generally better than six sigma as a framework and that the six sigma method is best implemented when problems are emerging. 
    So I’m wondering what the opinion is out there about six sigma as being effective mostly as something that reacts to problems rather than as a preventitive measure (as ISO 9000 was said to have been)?

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    #109691

    KBailey
    Participant

    Neel, I’d like to add something to the subjectivity discussion. There are two different cases that we call “subjective.”
    The first is when we rely on a human measurement system that we know isn’t as good as we’d like it to be. We see this a lot in sports, where referees or judges have to make calls or assign scores and everyone knows there is some subjectivity involved. Every measurement system has some degree of subjectivity, which we measure as reproducability and bias in a Measurement Systems Analysis. Sometimes it’s so difficult or expensive to measure that we accept a high level of subjectivity. For example, in a Six Sigma project, there’s only one best tool to use at a given time and one best way to use it, but it’s sometimes tough to get agreement on it. The only way to know 100% for sure would be to do the exact same project two or more times and see which way gets the best result. Difficult or expensive to measure…
    The second type of of subjectivity has to do with value judgments. Does something taste good? Is a particular color appealing? We can set up repeatable and reproducible measurement systems to quantify sweetness, tartness, saltiness, bitterness, etc., but that won’t tell us if it tastes good to a particular subject. Similarly, we can measure color in terms of precise wavelengths and intensities of light across the spectrum, but that doesn’t tell us if it’s appealing to a given subject.
    Management involves both types of subjectivity.
    On your new question: From a management perspective, Six Sigma is “easier” to use reactively. It’s easy to show cost justification by measuring how bad the process is before and after a project. When a process doesn’t exist, it’s hard to say how bad it would be if we don’t apply Six Sigma in the design. Even if we’re talking about preventing future defects, it’s easy to dismiss the benefits of Six Sigma by saying our managers and workers shouldn’t need Six Sigma to stop making so many defects or they must just be incompetent.
    Six Sigma does allow you to react, but the Control phase in DMAIC and the entire Design for Six Sigma approach are all about prevention.

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    #109710

    Mike Carnell
    Participant

    Neel Vaidya,
    I am going to be somewhat at odds with the rest of the posts. I don’t mind a “fool” question from a dumb kid … Typically the ones that tell you they are dumb aren’t. The professor that handed you the predisposed question in the first place probably is. If they were really interested in helping you learn to think for yourself it might have been something like “Is there subjectivity in the Six Sigma methodology?” instead you knew the answer they wanted right from the beginning. Give them what they want. The definition of a nanosecond is the amount of time your professors are relevant once you have a diploma.
    I agree with KBailey there are a lot of ways to solve problems with a variety of tools so there is subjectivity in terms of the method. As long as you are moving the right direction the subjectivity is irrelevant, the best way to get there is a subjective decision and that is a NVA discussion.
    Beyond that I don’t see subjectivity (DMAIC process) beyond the level of the alpha and beta risks that you establish. The process is a series of decisions. The tools are simply ways that reduce the “subjectivity” or risk associated with a decision. You make tradeoffs constantly accepting more or less risk/subjectivity based on the severity of the decision. Basically if you make a decision with a fair coin you will be correct 50% of the time, Average decision maker 80%, hi-pot personnel 85% but with stats it is your decision. If you professor wants it out 100% he is a complete idiot. If they see the subjectivity as a function of risk then they know it is variable and is also a function of consequence, time, sample size, and budget.
    DFSS is a different issue. Subjectivity is a function of the information you start with. Just as in DMAIC the tools should be eliminating optionsand reducing risk/subjectivity as you progress through the steps – the best map I have seen for the DFSS process is Tom Cheeks stuff at SDI. The map is a clear progression of soft tools to hard tools. It is funnel. Find a EE and get a picture of switch bounce and that is what the decision making process looks like. The DMAIC and DFSS process if viewed in that context are simply ways to reduce the magnitude and duration of the bounce. 
    The saving grace for Compaq Computer (during my time there) was the amazing way the Engineering groups worked with the Marketing group (Servers). When Engineering trusted the marketing groups information and marketing supplied a well defined target the combination was difficult to beat – unless you gave it away in manufacturing. History has shown that not to be subjective.
    Just my opinion.
    Good luck

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    #109720

    Deanb
    Participant

    In addition to KBailey’s 2 types of subjectivity, I would like to add a 3rd: Moral Judgements.
    Every process improvement effort faces moral judgements that must be made one way or the other, such as ranking which values are most relevant. For example, should an improvement favor loyalty to the company (cost cutting no matter the cost to other stakeholders)? Or should it favor other values such as not harming, satisfying customers, or helping employees better cope and succeed? Each situation may dictate different value rankings. All are value added dimensions, which need to be examined to understand the true and complete nature of any problem.
    Many practitioners in six-sigma try to think of themselves as being perfectly objective animals acting as detached agents in the improvement process. This is rarely the case. The change agent is always a part of the game that affects moral judgements and outcomes. Managing by the numbers is an important part of six-sigma, but not the only part. Doing the right things for the right reasons, and assuring that intents, means and ends are good for all involved, is the soul of six-sigma. The first helps filter the irrelevant from the relevant. The latter determines whether the organization truly gets behind the effort, sustains the effort, and ultimately transforms the operating culture into a higher level of business capability.  
    Regarding your characterizations of ISO as preventive and six-sigma as reactive, be careful of sweeping generalizations and apple-orange comparisons. These are not mutually exclusive things. Many organizations do both and utilize them as compliments of eachother. Similarly, both are also capable of being applied in either a preventive or reactive way. The key is the motivation (intent) of the mangement in doing either. As in all things, there are “right” reasons for doing ISO and six-sigma, and “wrong” reasons. In these instances it is the moral judgements that determine the difference. 

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    #109745

    Kim Niles
    Participant

    Neel:
     
    Regarding subjectivity, one of the main reasons why Six Sigma works is that it attracts top management.  Top management tends to react to concrete financial figures.  Therefore, it can be argued that Six Sigma should remain somewhat subjective as its success lies in part to its ability to expose subjective costs that always do exist in a company but were not seen under other initiatives.  
     
    Regarding preventive action projects, there are no restrictions on what a company must choose for its Six Sigma projects.  I argue that companies at three and four sigma have very obvious problems that need attention before thinking in terms of preventing other problems from popping up.  Along these lines, one would tend to think that companies operating at higher sigma levels would then have more and more projects that are preventive in nature.  Also don’t forget that Reliability oriented projects are preventive in nature. 
     
    Good luck with your class.
     
    Sincerely,
    http://www.KimNiles.com

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    #109765

    jeroen
    Participant

     
    Hi Neel,
     
    A good question indeed. However the bottom line is to make everything countable.
    It’s like Galileo Galilei (1564-1642) said: “ everything you can measure you should measure, everything you can’t measure you should make measurable”.
     Kind regards,

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    #109919

    Deanb
    Participant

    I certainly do not want to disagree with Galileo, but quantification is not the only means of accounting for ethical values. Perhaps when studying heavingly bodies, the game is about applied physics. But when improving people processes, ethical values are big factors too.
    Many ethical values must first being felt before thay can even be quantified, such as the values of empathy, responsibility, committment, justice, concern for others’ well-being, etc. You can count them if you try hard enough, but to what end? If you can innately feel a value’s relevance to a situation, this in itself can be worthy of rational consideration in its own right, possibly without any data.   
    Both subjective valuations and data measurements can arrive at misleading or fallacious conclusions if they do not follow rational principles, or are applied in irrelevant ways. The point is both objective data and ethical values are essential components of eachother in rational decision making anytime humans are involved, and neither can ever logically be a pure substitute for the other.  Values need objective facts to complete their meaning, and objective facts need values to complete their meaning. This I believe is the take-away truth we can get form Simon (quoted previously), and the fields of science, ethics and philosophy, as well as from the most experienced Black Belts and Change Agents who have learned from the school of hard knocks. 
     

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    #109921

    Mike Carnell
    Participant

    Jeroen,
    Interesting quote unfortunately it is from a time where there is a low probability that Galileo could even imagine the measurement capability we have today. The quote is completely at odds with the basic Six Sigma methodology. If you follow the process of funneling down the x’s associated with the Y (Y = f (x)) the whole point is to reduce the variables so we are only focused on the leverage variables.
    If we follow Galileo’s advice we will spend a huge amount of resources and time measuring things that have little or no effect.
    Just my opinion.
    Good luck.

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    #109958

    jeroen
    Participant

    Hi Mike,
    Thanks for your relevant reply. Please read my response: you are right the guy lived about 450 years ago. However a good quote can stand time.
    I don’t think we disagree that much. Funneling down the x’s, modeling them is, in my opinion, a step in the process of making them quantifiable.
    After modeling the x’s you have to collect data in order to confirm the model(s). After the confirmation of a model, you have control over your x and the x is quantifiable.
    By accurately choosing you’re x’s you are able to concentrate on the items that really matter and spent your energy on measuring the things that have the biggest effect. Kind regards,

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    #109973

    Mike Carnell
    Participant

    jeroen,
    I think we agree on the methodology. The quote basically says measure everything. We have both described a methodology that says some stuff isn’t important so don’t bother with it.
    Regards

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