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What is 6 sigma in plain language?

What is 6 sigma in plain language?

What is 6 sigma in plain language?

Hi all,

What is 6-sigma?

I am a CQT, have attended ASQ classes on SPC-I & SPC-II and have some basic knowledge of 6-sigma. My employer knows how to do business, but doesn’t understand technical things. Today he asked me what 6-sigma is, and I couldn't answer him in a language that he can understand. Could any one please answer my question in a very simple language that any one can understand?

I would appreciate any response.

Thank you.

RE: What is 6 sigma in plain language?

You could try telling him that 6 sigma is a gage of how much money is being made off a product or process.  The higher the number (Cpk) the better the yield.  I would recommend giving a "scale" of some sort to work with (say from 0 to 3), so that there is a realistic upper end to the capability numbers.


RE: What is 6 sigma in plain language?

Thanks PSE for your response. I am still looking for more responses.

RE: What is 6 sigma in plain language?


I have been trying to do better than PSE and don’t think I can but here goes.   I am a manufacturer with a degree in English Literature who never had a statistics course.  For me 6 sigma is a catch phrase.  It embodies a concept of Dr. Deming’s that the best way to make things is to make them right the first time.  This starts with designing manufacturing processes so that they can only be made right (Toguchi, robust engineering, etc).  We design our filter systems with one size bolt, one size pop rivet, etc.  

6 sigma recognizes that you will never hit perfection.   When I started decades ago 2% was a standard as in no more than 2% loss or defective parts or whatever.  6 sigma now means 3.4 parts per million.  (I know enough statistics to know this isn’t right but it is a big, commonly used number that expresses the concept simply).    The idea is that there is real cost in making bad parts.   Once it has to be sorted and reworked the possibility for profit has pretty well disappeared.  

We had a screw up in a prototype process and I am afraid we spent a huge amount of money to lose customers.  We had dedicated equipment in an electrocleaning process but it was still possible to switch a lead from cathode to anode.  We never did anything about it because there was never any need to move the lead.  Yeah, right.  Put in new equipment, needed longer leads, lead go switched.  If we had unscrewed the nut from the wrong post and thrown it away I would be several thousand dollars ahead.  Of course you don’t throw things away because they cost money.  

Try working this in with the 5 S’s (or 7 S’s or whatever).    If he is an accountant or sales type try explaining it in terms of organizing leads or sales history or in organizing accounts receivable.  If you are really lucky and he started on the plant floor then tell him that he already knows this.  You just set thing up so it is easiest to do things right.  Good parts, good tools, good training and a good workplace make good products.   About 20 of everything is done wrong in that unnecessary money and effort is spent to do things the hard way when there is an easier way to do it better.  


P.S.  I realize what kind of an explanation the above is.  However I am the guy who had a paper rejected by the Journal of Advanced Materials for excessive use of colloquial language.  I obfuscated and made it a lot harder to understand and they accepted it.  Now I know there is much better data in the phrase “the part failed under impact” than there is in “it broke when we hit it”.  

RE: What is 6 sigma in plain language?


We try to write our procedures at approximately a 4th grade reading level.  It seems to work well for the folks on the shop floor as well as the managers in the front offices .  Eschew obfuscation!

RE: What is 6 sigma in plain language?

search Google for six sigma, most results lead to ITT industries where I work. There is all the info you need on six sigma, in easy to understand reading.

RE: What is 6 sigma in plain language?

For the crib notes version go to  http://www.motivateeveryone.com/SSTsample.pdf Jay Aurthur puts out a cheap and effective simple SPC software that every qquality individual should have check it out and no this is not an adverstisement.

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