iSixSigma

Time Study

This topic contains 38 replies, has 15 voices, and was last updated by  bbal 12 years, 11 months ago.

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  • #43804

    Diorio
    Member

    I’m doing a time study. I’m writing down the exact time of all the steps of the operator (cycle start machine 1, cycle start machine 2, gage A, machine 1 stopped, gage B, debur part …), off my watch eg. 07:50:43. I’m trying to determine down time (when machines are stopped) and the causes. I’m trying to make sense of the data. Anyone with any suggestions? Thanks

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    #139426

    sixsigmadeewana
    Member

    Rich
    Time study is a very good tool and usually the person doing it is hated by the operators for obvious reasons.
    Some of the things that you could do are:
    1. Before the time study, sketch the layout and as you do the time study draw a diagram of the work is performed. This will help you to improve it and reduce time needed. Also, before the study, make sure you know what the standard operating procedure is. The study will tell you if the procedure is followed and if not, why it is not followed.
    2. You can actually come up with a formula for the total time (Total time = Variable time + Fixed time + Allowances). Ex: In boiler manufacturing process, MIG welding is extensively used. By conducting a study on welding of a 4 ft boiler, you can estimate the time required to weld a 6 ft, 8 ft etc…
    3. Look out for safety related issues
    There are several things you can do with it. What is your aim in doing these studies ? Tell us a little bit more and I am sure the experts here can help you.
     
     

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    #139436

    Diorio
    Member

    My 6 sigma project is thruput improvement on a machining center. I’m trying to show where all of the down time is going with individual tasks.  Ex. the cycle time of the machine is 2.5 min but at the end of the day the thruput is 5.0 min. I need to show where all the “overlaps” are (maybe he’s deburring a part when the machine is sitting) and then eventually remove any unnessessary tasks. Tasks include but not limited to: doing SPC, deburring, deburring for inspection, walking to get tools, changing tools, making offsets. So I wrote the real time down of the tasks as he preformed them and put it into spreadsheet (started at 7:00:00 and every six seconds increment). I don’t know how to organize it or show or justify the downtime.

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    #139437

    sixsigmadeewana
    Member

    I would suggest that you draw a flow chart of the current process.You could start by identifying the value added (VA) and non value added activities (NVA). Assign a NVA or VA to each activity that you have recorded. Find a way to reduce the NVA activities. You could use Pareto if you have more than 3 NVA. Re-arrange the work place, change the layout, use fixture that will eliminate or reduce cycle time or a fixture that could hold help machine multiple jobs at a time.
    If you need further help, post your email and I will respond to it.
    Good luck !!1
     

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    #139440

    Andejrad Ich
    Participant

    Okay…..again……time studies and throughput improvement is NOT a Six Sigma project; it’s a Lean project.  Six Sigma is designed to identify a process with output having some level of defects that can be reduced/improved.  The confusion about what does and does not constitute a 6s project is what dilutes its effectiveness.  Are burrs your defect?  Is there a way to reduce the occurrence of burrs?  What aspects of the process tend to contribute to the creation of burrs?  Are there machine settings that can be optimized to reduce the creation of burrs?  How would I design an experiment to optimize those settings?  What controls do I put in place to make sure the process creates minimal burrs from now on?  — See, that is Six Sigma. 
    Andejrad Ich

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    #139441

    GDS
    Participant

    Sum the time spent on each task identified and pareto by task. If you captured each task, as it sounds like you did, then the pareto will show you over the course of a day, week etc.. where your spending your time. You can also drill down to see when certain issues are happening. (more deburring later in shift)
    As the other poster suggested, you can also add a category of VA vs. NVA and also plott the amonut of time spent in each area.

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    #139443

    Ovidiu Contras
    Participant

    Rich,
    You can do some reading on Setup reduction techniques (most used is Single Minute Exchange of Dies – SMED). The principle is very simple:

    identify internal (setup operations that can be performed just when a machine is idle or stopped, such as mounting or removing tooling) / external ( setup operations that can be performed while a machine is running, such as transporting tooling to and from storage) operations
    modify the process accordingly
    convert internal to external
    streamline internal and external in order to minimize the total setup time
    Hope this helps…

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    #139448

    Jered Horn
    Participant

    Rich,
    It sounds to me like you need to utilize a Standard Work Combination Sheet.
    Columns: Step#, Work Content Description, Manual Time, Walk Time, Automatic Time, Work Content Graph (1 or 5 second time increments).
    List all the steps of your process.  This should be standardized, if not, that’s probably a starting point for your “project”.  If it’s a manual operation, place the measured time in the “Manual Time” column.  If it’s walking time…If it’s automatic time…  Do that for every step.  Then, in the “Work Content Graph” section, draw connecting solid lines (like stair steps) for the manual and walking operations.  Automatic steps are drawn with dashed lines and start at the end of the manual step that initiates them and are not connecting.
    The idea here is to expose situations where you either have a machine waiting on an operator OR an operator waiting on a machine.  If that’s happening, you have opportunities for improvement.  Can manual operations be sequenced differently?  Can machine cycle times be adjusted?  Can the layout of the work cell be optimized?  Can manual operations be automated?  Is there a tool that could be used to make manual opearations faster?
    You can/should also utilize a Time Observation Form during the actual time study.  It’s just a good form for documenting your study and it reminds you to time each process step/operation multiple times and take an average.
    Hope that helps.

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    #139450

    Andejrad Ich
    Participant

    This would be a really great thread on really any LEAN website;  it has no business being posted here.  Six Sigma is about defects reduction. 
    Andejrad Ich

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    #139458

    Heebeegeebee BB
    Participant

    Wow, that was truly an idiotic statement.   Lean and 6S dovetail rather nicely???
    For the life of me, I can’t figure out why so many folks around here get so “religious” about what 6s is or isn’t…Gimme a break!!!
    Six Sigma is just a wrapper, or roadmap bringing tools together to address variation and mitigate/eliminate it.
    THEY ARE JUST TOOLS…Why would I choose to ignore a certain tool or method that I could draw upon???Why would I exclude Lean tools/methods, because the website is about six sigma???
    Those who have worked in continuous improvement for awhile learn that to have a full tool box is an advantage.
    Man, what an ignorant comment Anderjad…
    SERIOUSLY.

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    #139461

    Darth
    Participant

    HeBe, if it is close to 5p where you are take the rest of the afternoon off, take a pill and wash it down with some good tequila or scotch.  TGIT.

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    #139463

    tottow
    Member

    Dear Mr. Ich,
    Could you please post for us the name of the person(s), organization, or entity who gave you the all-powerful knowledge to tell the rest of us what is and is not a Six Sigma project?
    I would really like to know so I could possibly go and sit at the feet of this fountain of knowledge and learn all that you have.
    My training taught me that Six Sigma is about variation reduction, improving processes, AND removing defects.
    I for one appreciate the technical knowledge you have helped to bring to this site.  Most of your replies to technical questions have been clear, well thought out, and correct, but I see no value in you continually pointing out to others what you believe are and are not Six Sigma projects. 
    I come to this site to learn whatever I can including beer halls in Texas burning down and the name of Mike Carnell’s daughter’s first horse.
    Maybe we should all try to learn what we can and try not to be quite so unforgiving of others.      

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    #139464

    Heebeegeebee BB
    Participant

    Unfortunately, It’s morning here…I could use a Pint of Guinness or some Dewer’s blended on ice though…
    Getting frustrated…early.
     

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    #139467

    Brit
    Participant

    What a crock.  Any improvement method can be used and their tools should be used to identify and solve a problem.  Quality improvement is about variation reduction and defect reduction. 
    If you wanted to use the SS terminology with this issue – simply set your goal based on customer needs in terms of turnaround time.  You meet it = good, You don’t meet it = defect.  You reduce defects, you improve the process.
    What tool(s) you use doesn’t matter.  The DMAIC structure is a good format for any project as are the tools in the SS and Lean areas of improvment.  You might want to use an ANOVA analysis to determine the effects of different time variables to the overall TAT.  That is not a traditional Lean approach.  You might want to use correlation or multivariate to see if one or more variables relate to each other, etc.
    Quit pigeon-holing Six Sigma – it gives it a bad wrap – unnecessarily.

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    #139476

    Diorio
    Member

    My customer is the production manger. I am trying to increase capacity with existing machines. This is just one aspect of my project as I need to look at the entire process from the order to shipping. I was given this project and I’m using what I thought were SS tools so I assumed I was doing SS.  

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    #139480

    Brit
    Participant

    Rich – I didn’t mean “Waht a crock” to you.  Sorry if you took it that way.  It was toward another poster.  People tend to pigeon hole issues into Six Sigma, Lean, et al.  So when someone tries to do that, it really gets my gut.
    You have the right beginnings of a project. If the production mgr is the customer (andthere are probably more), then have him/her develop goals for specific parts of the process.  Use that as your defect measure.  Also find the average (mean or median) to see how far your central tendency is from the goal. Also find your std deviation to determine consistecy.  Re-calculate your defect rate (DPMO), avg, and std deviaiton for a meaure of improvement.
    I would be careful in a capacity increase project and look toward the constraint.  You don’t want to increase the wrong process and create WIP.  Only increase the capacity of the slowest part of the process (or provide buffer stock if it cannot be increased).  Again, another theory (constraint theory) being included in a SS project.

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    #139481

    Andejrad Ich
    Participant

    6s has lost momentum in industry because of consultants bent upon selling it as, “Oh yeah, you can use this stuff for everything” (instead of reserving it for the purpose for which it was designed – defect reduction) and novices who are unclear where its intent and power truly lie.  Yes, you can use many of the shared tools to analyze lean applications – THAT DOES NOT MAKE A TIME STUDY EFFORT INTENDED TO ELIMINATE NON-VALUE ADDED TASKS A SIX SIGMA PROJECT!! 

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    #139482

    Brit
    Participant

    It can be a SS project if you reduce defects.  That is the measurable requirement.  And yes, consultants have tended to water SS down a bit, but limiting usage of the array of tools is plain rediculous.  If you remain such a purist, you will find a large opportunity for improvement wasted.

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    #139483

    Andejrad Ich
    Participant

    Variation reduction is part of six sigma for the very purpose of narrowing distributions such that smaller tails lap over the specified limits – resulting in………fewer units out of spec (i.e., fewer defects).
    Andejrad Ich

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    #139484

    Andejrad Ich
    Participant

    It’s not pigeon-holing; it’s specializing. 
    This idea that “Six Sigma can be used to fix anything” is killing it. 
    I have a great machine I want to sell you.  It’s a lawn mower.  It’s a great lawn mower.  It’s built to cut grass in lawns.  But you can also use it to trim your hedges.  But that’s not all — you can use it to vacuum your carpets.  And with these attachments, it can rototill your garden, be used as a concrete leveler, remove wallpaper, strip paint, spray paint, chip sticks, dig postholes, powerwash your car and serve as a floor jack and a bug zapper. 
    See, the more you read there, the more you have to question how good it really is as a lawn mower.  Six Sigma is a great lawn mower.  If you want to do those other things, there are tools built for those too. 
    Andejrad Ich 

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    #139485

    Brit
    Participant

    Fo rthe novices out there, Lean and SS work very well together, as do the tools.  A verfication of this is the evolution of Lean SS.  Motorola, the Six Sigma Academy, BMG, DuPont, Honeywell, GE, BP Oil, Cisco, Blue Cross, Johnson and Johnson, Pratt&Whitney, Volkswagon, Home Depot, Xerox, Cisco, etc….  all use or train Lean Six Sigma.
    Oh, and yes, iSixSigma is a presenter at the 2006 Lean Six Sigma Summit – so LEAN has a place at this forum.
    Bottom line – you CAN use the SS DMAIC structure for any improvement project.  Dependig on the type of data you are dealing with will direct you to which tools you should use for the analysis and improvement. You don’t have to do EITHER Lean or SS.

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    #139486

    Brit
    Participant

    I agree to some extent. However, if you don’t allow 1 thing to evolve naturally – which is what I think Lean Six Sigma is doing, then you reduce the opportunity for growth and innovation.
    By taking 1 product, idea, etc., and adapting it to meet other needs, you often end up with a better method than the original.  There is also the chance that you end up ruining the original, but I don’t thinnk that is the case here.  How many uses are there for the shoelace other than to keep shoes tight on your feet?
     

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    #139487

    Andejrad Ich
    Participant

    “Lean Sigma” evolved solely as an attempt to legitimize the “you can use this stuff to improve anything” sales pitch. 
    If you are doing time studies to remove non-valued added steps, that’s right-out-of-the-book “Lean.”
    Basic litmus test question:  what is the process sigma level before improvement effort and what is the process sigma level after the project is completed?  There’s only one way to calculate that — using occurrence of generated defects.  If you can’t assemble the project in terms of measurable generated defects (per million opportunities), then there can’t be a sigma level, and if there isn’t a sigma level, then it can’t have been a six sigma project. 
    Andejrad Ich

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    #139488

    tottow
    Member

    Au contraire! (Snoopy; Peanuts the comic strip) 
    You can reduce variation without ever having experienced a defect. 
    They are not mutually inclusive (i.e., you can have one without the other).

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    #139489

    Andejrad Ich
    Participant

    But if you haven’t experienced a defect……(as in units out-of-spec)
    ….then why on Earth would you be working on improving the process?
    If you aren’t running occasionally out of spec (because maybe you don’t even have a spec), who cares how wide the distribution is?
    And again, if you don’t have a spec and so can’t generate defects, then you can’t calculate a sigma level……and….therefore…… the effort can’t be a “Six Sigma” project.  Just call it something else…call it what it is. 
    Andejrad Ich
    P.S.  I’m really only posting today because my mom isn’t home and I’m bored

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    #139490

    Brit
    Participant

    The original post:
    I’m doing a time study. I’m writing down the exact time of all the steps of the operator (cycle start machine 1, cycle start machine 2, gage A, machine 1 stopped, gage B, debur part …), off my watch eg. 07:50:43. I’m trying to determine down time (when machines are stopped) and the causes. I’m trying to make sense of the data. Anyone with any suggestions? Thanks
    If you have a goal set for down time, throughput, capacity, output, etc. you can use the defect measure.  In fact, I bet the the real question of Rich’s production mgr is output – how many good things am I producing at the end because I seem to be running a lot of overtie to get the stuff out the door.  That is what is usually translated when a production mgr wants the answer to “I’m trying to determine down time (when machines are stopped) and the causes.”  If they create a goal, they can analyze it and improve it via any method they wish (lean, ss, constraint mgmt, voodoo).  If they don’t know where they want to be, how will they know when they get there?
    I do believe that Lean tools will help them solve their issue, but ss tools can help them too.  It should never be one or the other.  And, having a project in the DMAIC format wouldn’t hurt either.
    By the way – consultants aren’t the only people that think Lean and SS together is a good idea. See previous post of companies using it.  I am not a consultant by the way.

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    #139491

    tottow
    Member

    Again, I will ask you; who told you there had to be a calculated sigma level to have a “Six Sigma” project?
    If you have to have a defect to want to improve a process where did the phrase “continuous improvement” come from?
    You insinuate there has to be a defect before you need to improve anything.  Do you think that is what got Toyota and Honda where they are today (and yes, I know they don’t use Six Sigma).  Do you not think that is why Ford, GM, and Daimler/Chrysler are still where they are?
    You said in one of the other posts in this thread something about this type of thinking coming from consultants watering down Six Sigma to try and make it do everything.  This “philosophy” I am advocating was taught to me from company supplied material in 1999 and we had not seen any “consultants” in the organization since ’95, I believe.  You can ask Stan to verify that.
    I am sorry your mother is not home and you are bored and I am not trying to pick a fight, but for all of the intelligence you seem to have from some of your other posts, I cannot for the life of me figure out the narrow mindedness you have regarding this particular subject.
       

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    #139492

    Andejrad Ich
    Participant

    By sticking to a clear definition of what is a real Six Sigma project (which I think I’ve been pretty clear about), we can all avoid the many crappy B.S. project presentations in PowerPoint we have all had to sit through where the candidate has something on the Define slide and something on the Analyze slide and something on the Improve slide and in the end we’re all expected to clap when…in reality….it was all crap.  Ill-concieved, poorly executed, inconclusive…but, because it was in PowerPoint, it must have been well done.  I’ve seen absolute nonsense presented as completed Six Sigma projects.  Starting with a clear definition of what is Six Sigma brings the whole effort up to a new level of execution – and it makes it easier for the project owner to actually KNOW what he/she is supposed to be doing.  My point is – with clear definitions and the clear expectations that accompany them – we can avoid the total crap that too often hangs its hat on the Six Sigma sign (and so brings 6s down every time it happens).
    Andejrad Ich
    P.S. I think I hear mom’s car in the drive.

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    #139493

    Sigmordial
    Member

    Not sure if I agree with the implication associated with your rationale for the emergence of Lean Six Sigma.  I believe it is a natural evolution based on business needs relative to improvement.  Regardless of the product or service, companies strive to provide the customer with what they want, when they want it, with the best utilization of resources.  Having two separate programs to improve these aspects is not really a lean approach to improvement. 
    Here are some of the advantages that I have noticed with a Lean Sigma approach:

    Enables improvement efforts to consider the classic contradiction of speed versus accuracy within the same project space.  At the very least, project charters can be constructed to  improve accuracy without degrading speed.  And the project leaderss have the skillsets to achieve these objectives
    Expanding upon this, improvement efforts within the organization are not stove-piped.  Nor do you have 2 separate camps trying to maintain relevance in the same improvement space.
    It makes sense to cultivate an improvement culture within the organization, not just a Lean culture or a Six Sigma culture.  Lean Six Sigma is a program that enables the organization to resolve almost any performance gap (quality, cost, or speed)
    Improvement opportunities can actually require both approaches

    One of the sources of waste is defects — Six Sigma requirements in the Lean space
    One customer requirement is delivery — Lean requirements in the Six Sigma space
    Most purist approaches to Lean rely on point estimates for time measurements, not considering variation, as well as the associated uncertainty introduced with sampling
    From a learning & education perspective, you do not have to train 2 separate methodologies.  Nor do you have to hire both Lean Masters and MBBs to provide the coaching
    About the biggest disadvantage I have noted is the incredible resistance from some of the purists in both camps. 

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    #139494

    K. Lo
    Participant

    Only had to read the first few to agree: even though the machine itself may have a 2.5 minute cycle time, the extra 2.5 minutes might have all VA steps, which means that the actual cycle time is not 2.5, but 5 minutes, and that’s your baseline for that step.
    What does your SIPOC say the focus is, on this one particular step or is it reducing cost to produce…or something else?  You and your team need to remember that people are not machines and you have to account for the human element.  If a person is fixing something, then the project is not in how much time it takes to fix something, but why does that part need to be fixed in the first place?
    Good luck.
     

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    #139496

    Heebeegeebee BB
    Participant

    Andejrad,
    You are completely wrong.   “Six Sigma”, as a package was an assemblage of existing tools.   The uniqueness comes from the road map or methodology wrapped around those tools.   Bottom line, Six Sigma relies on mitigating/eliminating variation and a focus on processes.   All of this is done in the spirit of Continuous Improvement.   Continuous Improvement means change.   On the whole, Humans like security and change upsets that balance.   I sense this in your posts.   The real question is, why are you so resistent to change and adaptation of Six Sigma to include Lean, TQ, etc???  Which of the four resistance typologies are you exhibiting?
    You see, Change Management and OD are included in the methodology as well…Remember, over 90% of what “We” do is soft-skill, change management activity, the other 10% are hard skills (i.e. Tools) – The “Trained Monkey” stuff.
    You’ve rehashed at least three times that SS is watered down and by being inclusive, you mitigate the effectiveness.   Talk about trapping yourself in a box of your own making…
    Show me concrete data to support this.   I’ll save you the time…You can’t.   All you have are anecdotal, discrete symptoms that you attribute causative status too.  
    Remember man, you can’t bend the spoon, because there is no spoon.
     

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    #139498

    Brit
    Participant

    If you aren’t meeting a customer demand it is a defect – fairly elemental. If you have a time or capacity goal and do not meet that  then it’s a defect. You can’t argue this fact anymore – doing so will waste a lot of time for readers and myself.

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    #139499

    Brit
    Participant

    Well stated.

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    #139507

    Darth
    Participant

    You tell’em Sigy.  Sounds like you learned this the hard way….fond memories of MCap.  Will be your way in a few weeks for the bi-annual festivities.  Hope all well.

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    #139510

    Anonymous

    Andejrad,
    Anyone who has actually found the true cause of defects will not claim Six Sigma is all about defect reduction. To claim it does only demonstrates one’s own lack of achievements.
    In the past, I gave you an example of an exception to the ‘quality theory of defects,’ which you’ve ignored. There are many processes where yield has to be optimised without reducing ‘defects.’ Agriculture provides just one example ….
    However, I do agree that any project must have a business case and must a clear definition of goals.
    Andy

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    #139511

    MB
    Participant

    Andejrad,
    In reply to your post about the lawnmower……
    If a joiner was working on a roof and was having a break for a ciggarette and the ash set the roof a light would he try to put the fire out with his hammer? or would he use the cup of coffee by his side?
    My point is just because something is not in the six sigma tool set should we not use it if it improves our process by x%.  Six Sigma and lean fit perfectly together, and in most cases sigma levels could be set for a lean project. ie the TAKT time required by the process is 5 minutes, therefore DPMO can be set and therefore sigma levels. 
    I am very new to Six Sigma and all your posts I have seen in the past have been excellent…… but not this one!
     
    MB

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    #139518

    Andejrad Ich
    Participant

    Actually, “Six Sigma” established the use of existing tools on a backbone of DMAIC (an invention of Six Sigma) to identify process parameters contributing to successful/failing output (i.e., defects) and measuring the situation in sigma level (which requires a spec to do).  It’s designed to minimize defects.  Variation reduction and process centering is indended as part of the package…..to reduce defects. 
    Show me a “Six Sigma” project based on a process that can’t be flow charted as a true process and having no measurable occurrence of defective output that can be calculated as a sigma level and I will argue every time that it is NOT a “Six Sigma” project.  I’m NOT saying that whatever it is you are talking about isn’t necessarily worth working on;  I’m just saying that clear definition divides truly value-adding Six Sigma work from all the crap that is passed off as Six Sigma work.  I’m just saying DON’T call those other things “Six Sigma.” 
    “Hey, Tom increased sales by 10% last month!”  “Great!  Is there any way we can write that up as a Six Sigma project?”  “You bet we can!”
    To say that an effort to reduce cycle time of a widget line is a viable candidate for a Six Sigma project is complete nonsense.  If you’re trying to reduce the generation of defective widgets, then YES…..THAT is Six Sigma.  Go ahead and do all the industrial engineering time studies you want…but good luck reporting your improvements in sigma level. 

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    #139588

    Scott
    Member

    While I agree that 6S and Lean are OFTEN mistaken, for a given process, such as the one mentioned here, defects could be seen as the unnecessary steps in the process.For example:
    SIX SIGMA: Out of a million parts made, how many of them were made without wasting time doing extra deburr?
    Project: Ensure operators replicate the same process every time (eliminate variation in the process)LEAN: In the making of parts, how much time is wasted doing extra deburr?
    Project: Eliminate the time wasted doing extra deburr (eliminate the waste itself)

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    #139649

    bbal
    Participant

    helo
    Gentleman , send me the data or display and i can guide u how to analyse and interpret th edata u colected from the time study u r doing

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