From: email@example.com (Brian Teasley)
Subject: Re: Design of Experiments Workshop in NYC, SF, Miami
Date: 9 Dec 2002 14:46:25 -0800
References: <3DF00F90.firstname.lastname@example.org> <email@example.com>
NNTP-Posting-Date: 9 Dec 2002 22:46:26 GMT
John Larkin wrote in message >
> this is actually an interesting issue. I've read a bit of the DOE
> stuff, and that seems, to me, to be nearly my natural enemy.
> One cannot use DOE to design bridges, skyscrapers, or space shuttles.
> They have to be *right* by design, with small margin for ignorance. If
> electronics and software are designed with similar levels of theory
> and discipline, there's no room or need for DOE or Taguchi techniques.
Sure, I agree with you. I've written some software code myself, and
have been involved in decent sized software development projects as
well. During those times I have never thought of any reason to apply
any DOE techniques.
In reviewing the posts, there might be a little confusion about the
term "test design" that I used. It refers to the way a test is set up,
rather than a specific design of a "product" that is put together
solely for a test.
DOE methods are used when you do NOT know exactly how a process works.
If your designed skyscraper is using some new type of glass, there are
plenty of temperatures and times and chemicals, etc., that influence
the thickness, strength, opaqueness (?), etc., of the glass. What is
the optimal combination of chemicals levels, temperatures, etc. to
make the glass?
A "Full Factorial test design" would be an experiment in which you
test all combinations of your chosen variables and their selected
levels. You conduct your "test" or experiment, and carefully analyze
the glass thickness (or opaqueness, or whatever) against all of the
different settings of the different variables.
As for the space shuttle, I know they DO run simulations to test
designs, and they have some very serious computers to do the work. How
do different angles of attack (when landing) and ambient temperatures,
humidities, etc., effect the shuttle? (Including the nose cone and the
famous "tiles"). The manufacturing of the tiles is certainly an area
for DOE application. I haven't been involved in the shuttle
simulations directly, so I don't know if they use DOE in any way or
not, or even exactly what it is that they are simulating. I have been
involved in the manufacturing of parts for the project, and DOE
certainly is used in along the way.