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Need Proof that operators that use gage and make parts need to do MSA

Discussion in 'Gage R&R and MSA - Measurement Systems Analysis' started by Mark Paul, Aug 10, 2016.

  1. Mark Paul

    Mark Paul Member

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    Silly, yes. Serious, Yes. Even after 5 years, someone in management is questioning QA's need for 3x3x10 MSA to be done by the operators that run the parts and use the gages.

    Question I need proof of: Why can't competent, but, non-production, indirect labor people do the Gage R&R. Forget that it's common sense. Where is it written that it MUST be done that way? I can't find anything direct in the TS MSA Manual. Thanks!
     
  2. ncwalker

    ncwalker Well-Known Member

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    If you invite me and my brother over for a beer and we do the gage R&R and it fails, management is going to say that we aren't the regular operators of the gage. Of course WE can't do it.

    If that's the case, then the only people who CAN do it are the regular operators of the gage. Any other demonstration (good or bad) is meaningless.
     
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  3. Golfman25

    Golfman25 Well-Known Member

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    Common sense would suggest the operators who use the gage should collect the MSA data for best results. I think somewhere in the MSA book it states that people are part of the MSA system. Find it and use that for your justification.

    However, riddle me this. You have 25 operators. All using the same gage. Does everyone need to participate in the MSA? So it's 25 x 3 x 10? Or can you pick 3?
     
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  4. ncwalker

    ncwalker Well-Known Member

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    Ooooooh. Good riddle. OR if you are using the same 1" micrometer to check three different journals on a shaft, all ground, do you have to do an MSA on each of the 3 journals? Or is one of them good enough ....

    Bev D is going to come on here and tell us there is no substitute for thinking .... I can feel it in my bones.

    But she's right, there isn't a substitute for thinking. And the problem is ... once I write a set of instructions (MUST be 3 operators, with 3 trials on 10 parts) someone like Golfman comes up and has a special case. Which is the inherent problem with step by step instructions. They are VERY specific.

    So the answer to Golfmans riddle is you can pick three. You are trying to demonstrate the gages lack of sensitivity to ANY 3 operators. Next question - WHICH 3? Your 3 best? Your 3 worst? Random? In statistics, the answer is random. But a Gage R&R isn't a statistical study, it's a designed experiment that USES statistics. To truly check the gage, one would pick your worst 3. If they can do it, anyone can ....

    But WAY back up to the ORIGINAL question - I would also add - it sounds like Mr. Paul is having the age old fight with management who doesn't understand the necessity of something. More free advice: respect the fact that management is trying to control costs, as well. In my shaft example above, you would be wasting time to use the same micrometer on the three different journals. Pick the one with the tightest tolerance and just do that one. That's not an unreasonable superposition assumption to say it could then measure the others.
     
  5. Miner

    Miner Moderator Staff Member

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    No. The three are just a sampling of the 25 and should be representative of all. In the ANOVA method, the operators are treated as random effects (i.e., a subset of all possible). If they where all possible operators, they would be treated as fixed effects. This affects the math done in the background of the ANOVA method.
     
  6. ncwalker

    ncwalker Well-Known Member

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    Sure. Hit us with MATH, Miner.

    Mr. Paul has to convince management. :p

    Honest question, however - you do say the operators are treated as random effects so you pick three. Would it not be advantageous to pick the worst three? In statistics, you randomize what you can't block and block what you can't randomize. To me, picking the worst three seems to be good blocking. You would get the worst Gage R&R, but if it passed, I would think you would be much more confident you had a good gage.
     
  7. _Zeno_

    _Zeno_ Member

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    I would argue that 6.2.2 would cover your needs nicely! (especially 6.2.2c)


    upload_2016-8-10_15-41-38.png
     
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  8. Miner

    Miner Moderator Staff Member

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    You would probably get the worst GRR if the operators were truly representative (i.e., included best, worst and typical). This should tend to maximize the Reproducibility variation. The differences between operators would definitely show up clearly on the graphs.
     
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  9. Mark Paul

    Mark Paul Member

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    That's what I would like to say to them......
     
  10. Mark Paul

    Mark Paul Member

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    Thank you VERY much!
     
  11. Bev D

    Bev D Moderator Staff Member

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    OK here I am.
    First: Zeno has given the OP a plausible section to refer his management to. Miner has provided the statistical reason for random selection of operators. All very good answers of course.

    BUT, as I get closer to retirement I despair that we as quality practitioners have failed. Not due to lack of trying but due to the natural human condition to believe whatever they want to believe regardless of facts or logic. Even simple math completely eludes critical elements of the population as does the ability to recognize the truth, do the right thing and certainly the ability to apply critical thinking skills to even the most simple of situations. (Deming's profound knowledge) Mark's management is just one more example of this...they aren't thinking, they are searching for a rationalization to not do something and if it isn't written in the law they won't do it. They must have a yes or no answer - that they like. The logic of why gauge R&Rs are valuable won't ever sway them. But they will become enraged when poor quality product escapes to the field and the company has to pay for it. No doubt they will just blame the customer or the operators or Mark for letting the defects escape. So riddle me this: how do we turn this around?
     
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  12. ncwalker

    ncwalker Well-Known Member

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    You must tie the metrics to the checkbook. I hate ppm as a metric for GRADING. It is an excellent metric for TRENDING. The problem is when you get into a larger company situation. In my company, not all locations calculate ppm the same. Yes, I know the calculation is bad parts in/total parts in * 1E6. But the number of bad parts .... I have locations that say that if they receive bad parts, and the supplier pays for a sort, it should not count against the supplier. And those parts are backed out of the system. Clearly the motivation by the site is to have the lowest incoming ppm, otherwise top management gets upset. But how in the hell does that help us IDENTIFY THE BAD SUPPLIERS?

    That's the culture we have to change. Data is NEVER bad if it is true and accurate. Data that is over-massaged is valueless.

    Another example: why are our DMR areas all tucked away in a corner? Because they "look bad" when people come. Why is the DMR area not right inside the doors to the shop where everyone is tripping on it if the pile of bad parts gets large? It needs to be in your face so it gets attention. We have to shift focus which is 90% "look good" and 10% "works well" to more 50/50. You lean and visual management guys take note - I'm not to happy with you. Sexy visual systems that DON'T WORK are a distraction. I hear a lot about putting stuff in place, and not nearly enough "circle back around in 3 months and decide if it is working." We SAY Plan-Do-Check-Act, but too often we Plan-Do-Forget.

    I honestly think it is the TS culture that has hurt us. The natural state is to fall in line with a "recipe." Does it have to work? No. It has to look like other places. Guess what? A glass factory and a cloth factory and a metal factory and a rubber factory are NOT THE SAME THING.

    The key is to tie in quality to the checkbook. THEN let them see what happens to the checkbook when the quality discipline goes away. But here's the other thing, JIT manufacturing isn't helping us. Everyone has it in their heads that minimizing stock is an important cost savings. And it absolutely is, but the target is NOT zero. The problem with zero stock is that it REQUIRES every part be perfect, every time. I don't know about everyone else, but what I observe in many locations is everyone patting themselves on the back about near zero stock levels, but then go look at the receiving dock - air shipment after air shipment to replace parts that are bad. And that bill is SO HUGE that it masks almost anything about quality. The result is a culture of witch hunting develops. Because at that point, any blink in the supply chain from quality - even if it is just an honest mistake - results in huge costs. And we spend our time almost like lawyers assigning blame instead of solving problems. Many of which would go away if we just kept, say, a week of inventory instead of a day. THEN what I notice is the line folks figure this out. And they squirrel away parts, you know, just in case. But these parts sit. The design changes a bit, they don't know about it, parts get tight and these "old" parts get introduced into the supply chain. THEN your traceability goes out the window and you sort everything.

    It is ridiculous how often it goes down this way.

    So.... after the rant .... my opinion is.

    1) We start getting smart on how to calculate proper inventory levels. Find the intersection of the cost of carrying inventory curve with the cost of expediting curve. This will eliminate a lot of unnecessary expediting costs industry wide. We actually have gotten good, as an industry, at lowering defects. You just can't see it compared to the EXTREME shipping costs.
    2) THEN, when those giant numbers disappear, we sensibly tie quality metrics to the checkbook. That is the only number top management understands. My experience is that all the other numbers are utilized only on the defensive - to obfuscate and divert responsibility for problems.
     
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  13. ncwalker

    ncwalker Well-Known Member

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    Then SAY it. Approach them in a way that isn't in your face and arrogant. Tell them this is how it looks from YOUR perspective and you want THEIR take on it so you understand THEIR perspective. Say "as a quality engineer, you pay me for my opinion from a QUALITY standpoint. Here is how this situation works, boss. And after I tell you I want to hear how it looks from your end so we can find a reasonable solution." There are 3 possible outcomes:

    1) The hear you and the seeds of change are planted.
    2) They "put you in your place" logically. (They like to be right, this, to me, will be most likely). But ... the seeds STILL will be planted.
    3) They "put you in your place" emotionally - belittle you - then you find a different job. That's not a healthy place to work.
     
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  14. Jennifer Kirley

    Jennifer Kirley Moderator Staff Member

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    By changing human nature? Let's face it, people's motivation varies and the outcomes/repercussions will continue to be subject to that. I have noticed two things since I got started oh-so-many years ago:

    1) Every horse can reserve the right to die of thirst
    2) People's snafus tend to replay themselves, and keep the ancient Greek tragic plays somehow relevant.

    We can do what we can: collect and present the facts, offer insights and ideas, provide guidance when asked, and then do the best we can in hopes the people in charge make good decisions. In the end, we must retain our integrity and self esteem or it's time to move on.

    ...2 cents...
     
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  15. Mark Paul

    Mark Paul Member

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    Nice rant, ncwalker!
    3) They "put you in your place" emotionally - belittle you - then you find a different job. That's not a healthy place to work.[/QUOTE]

    I've been down the "get another job" road as many on this site probably have. After a while it's the same pile of stuff disguised as pretty, shiny objects.
     
  16. Mark Paul

    Mark Paul Member

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    Jennifer,

    I have been reading you for over ten years. I hope you don't stop writing after retirement.

    In the end, I keep my integrity because I couldn't live with myself if I didn't. I make them budge because we go through this Gage R&R discussion every year and they come around when they realize that I know that they know that what I say is correct, just like it was last year and the year before. Changing jobs just isn't an option for me.
     
  17. Jennifer Kirley

    Jennifer Kirley Moderator Staff Member

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    You are very kind Mark.

    I don't see myself retiring anytime soon. I don't have the money.

    After fleeing a painful 4-year work experience with a sore forehead (from banging my head against the wall, dealing with the owner of a 35-person family owned machine shop) I went to work at a Boeing supplier in the Seattle area. I was overjoyed, feeling sure I would once again enjoy a mature QMS in a place that had its act together. I soon learned I was wrong.

    That experience taught me two things:
    1) The management systems are about people, and people can have the same virtues and faults in any given place. Provincialism was not the issue, nor was size or the system they were somehow certified to.
    2) Given the case of #1, I may not be able to change things, at least quickly or in a noticeable way; I had to decide how to feel.

    It looks like you are in that place. Right where you belong. Keep up the good work! :)
     
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  18. charanjit singh

    charanjit singh Member

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    The entire discussion highlights what Jennifer rightly said, it is 'about people' always...
    On a personal note, reading about the experiences of many people here makes me realize how lucky I have been in all my 'Quality' career from 1957 onwards. People whom i worked with, were very supportive of the recommendations and actions I took or proposed to take in the interest of their reputation for Quality. So much so that even now, approaching my 90th birthday the company I have been associated with since 1991 would like me to continue giving my advice as often as they need.

    I earnestly hope everyone gets luckier and luckier in their Quality efforts in the days to come.