Re: My Sigma's bigger than your's-1

[GrantBlair@aol.com]

In a message dated 10/8/2000 7:17:59 AM Eastern Daylight Time, 
jsdwd@samart.co.th writes:

<< This factory has come late to the control charting method and is only now
 beginning to control chart some of their key quality characterisitcs such as
 smoothness and the initial control charts show an abundance of special
 causes (as is often the case....NOT ALWAYS!).  Simultaneously the fixture is
 shown on the basis of some trial runs to markedly reduce variation in
 smoothness.
 Would it be your position Mr. Blair that the new fixture should not be
 introduced to the process until all the other special causes were
 eliminated?  Would it further be your position that introducing the fixture
 at this juncture would increase variation? >>
Now, let me explain what would happen if I had accepted Mr, Dowd's
proposal for the new fixture:
As soon as the other engineers in the plant with big sigmas understood the
"rules", there would be a line of them knocking at my door, each one with his
"best effort" improvement for the process...Tools, computer programs, 
etc.,etc.
Here are the "rules".
>>>basis of a few trial runs<<<
Translation: It only took a few tries to get a run with the numbers we wanted.
If it took a lot, the code would be "after extensive studies".
Darrell Huff provides an excellent example in his book "How to Lie with 
Statistics"
>>>>Markedly reduce variation in smoothness<<<
Translation: Don't know if it's statistically significant, but the number is 
big enough
to justify the cost of the fixture. I recall a Plant Manager (also a Deming 
advocate)
who added up all  SUCCESSFUL savings projects completed under his
management. He concluded we would be able to shut the plant down for about 3 
months, since we were (obviously) running ~ 120% yield
>>>initial control charts show an abundance of special causes<<<
Translation: Yeah, I know Grant keeps asking us to understand the customer, 
and learn from special causes how to understand and improve our process , but 
Innovation is a hell of a lot more fun for a person with a big sigma. That's 
his job, not ours. Besides,  special causes always go away if you wait them 
out--just look at the charts.

And common cause variation would increase throughout the plant, even to the
point of overwhelming Special Cause, (which would further justify the big 
sigma
engineer's claim.), until a cry for mercy  would come up from the customers 
to the God of the company.
And God would say, "Cast Out The Big-Sigma Engineers, And Their
Tools, Fixtures and Programs Into The Depths of Hell"
Then the engineers with small sigmas would say "Told You So!!! Now that
the traditonalists are in charge, we will return this plant to the processes
which were so successful in the past"

Now, here is my homework for the group:
What will happen to common cause and special cause variation now that
the small-sigma engineers are in charge? Try to be brief, but feel free
to provide some examples.

GrantBlair@aol.com
Ninety Six SC