[PLUG] UML users?

Phil Tomson ptkwt at aracnet.com
Tue May 20 10:35:03 UTC 2003


On Tue, 20 May 2003, Jeme A Brelin wrote:

>
> On Mon, 19 May 2003, Phil Tomson wrote:
> > No, I'm not trying to trash it.  I'm trying to find out why people use it.
> >
> > For me it seems like a step in the wrong direction, but if I can
> > understand why people choose to use it maybe I can understand why people
> > want to go that way and then offer them alternatives ;-)  I really do
> > think there might be better methodologies....
>
> I think Rich's point is valid despite the "shove off" language.
>
> You say that it seems like a step in the wrong direction before really
> knowing much at all about it.  You assert counter-points to the individual
> statements of those who use the system but you fail to take those
> statements in aggregate appreciate the way the tool is used regadless of
> how you might use it yourself.  You can't learn the usefulness of
> something if you're just trying to find out how useless it is.

Oh, my!  Email is such an imprecise communication medium, eh?  It seems
I've come across as some sort of very closed minded person.

Actually, I've read some of the articles on UML by Booch (several years
back, I admit).  Recently we had some discussion about UML on another
list I'm on and we had a bit of a debate - I guess there were a couple
of other old hardware engineers on that list because I found I had some
agreement about not wanting schematics for software.

I've actually considered learning UML, but time is limited so I need to be
choosy about what I invest in.  That's why I try to find out what is
motivating people to move in that direction.  I'm coming from a different
industry where I witnessed the reverse happen: there was a movement away
from graphical design descriptions toward textual ones, and at the time
this was a rather radical shift.  I witnessed this shift first-hand
during my career.  When I graduated in the mid-80s we drew schematics
exclusively - very few people had even heard of HDLs or any kind of
textual description of circuits.  By the mid-90s HDLs were making inroads
and mixed schematic (graphical) and HDL (text) designs were being done.
Now in the ASIC and FPGA world it's very rare to find schematics being
used at all - the paradigm has completely shifted and hardware engineers
are definitely more productive because of it.  There is no way that the
types of chips being designed now could be done in a timely fashion using
schematics.

So please don't think of my criticism as merely taking potshots at
something I know nothing about; I'm merely offering my observations based
on what I've seen happen in the world of chip design over that last
fifteen years.  You can take those observations as instructive as related
to software design, or you can write them off as totally unrelated, that's
up to you.

>
> Now, I have never personally worked with UML and so I really have no
> comment on its usefulness as tool for the programmer.  However, I have
> seen PLENTY of bad code badly documented and I welcome anything that will
> help describe the design of a program for future maintainers and
> modifiers.  I think this is really a difference in philosophy more than a
> difference in technology.  To me, the social aspects of how a thing is
> done far supercede the efficiency or expedience of how a thing is done.
> I personally believe that the purpose of work is to make the world a more
> pleasant place.  The inconvenience of using a cumbersome tool (if, indeed,
> that's what we've got here) in the design phase seems to be a way of
> paying a small cost in pain up front for alleviating the long pains of
> future developers who must work from your code.  Bad code never dies and a
> little inconvenience today could prevent a lot of inconvenience in all of
> our tomorrows.
>

Schematics were fine for documenting small circuits.  If you only needed
two or three pages of schematics it was a reasonable way to understand how
the circuit worked.  But for large systems it was extremely awkward.  I
recall that in my first job out of school they handed us a huge three-ring
binder full of hundreds of pages of schematics for a very complex chip
tester and we were supposed to go off and study them.  I'd take them home
and read them trying to figure the thing out.  You'd be chasing one signal
and then it would get to the end of the page and there would be a little
note about the other pages the signal went to... oh, the pain, I'm trying
to forget it. ;-)

Anyway, please excuse what seemed to be a viceral reaction against UML; it
just seems as though we hardware engineers have been there and done that
and I'm not really sure I want to go back there.

Phil





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