Loosely coupled may not be a term of endearment

by Sean McGrath

June 9, 2003 —

What follows is a true story. I promise.

I had some business to transact with a financial institution in my local
town. Simply put, a transaction that should have happened ages ago had
not yet happened and I needed to chase it up.

The manger consulted the computer system and confirmed that SNAFU[1] was
the order of the day. My transaction had still not completed.

The apologetic manager looked up from the computer screen at me and
intoned gravely:

"Sorry, but our system is terribly loosely coupled".

At that point, I had one of those Matrix moments. The kind where all the
action stops but the observer does a 360 degree loop looking at the
suspended action from all sides.

As readers of this newsletter know, I'm a big fan of loose coupling. In
fact, I'd go so far as to say that it is the focus of my professional
interests this decade the way that XML was in the last decade. For me,
loose coupling is a *positive* thing, a term of endearment. It's an
excellent way to build reliable, flexible, long lived IT systems.

So, confronted as I was, by a situation where the term "loosely coupled"
was being used with a negative connotation, I was naturally taken aback.
What could be going on? Perhaps this financial institution manager is a
'closet techie' and an avid reader of ITworld articles? Perhaps he has a
technorati watchlist[2] and avidly follows everything I blog about?

That self-aggrandizing fantasy remained credible in my head for about a
picosecond before sanity returned. The interesting truth of the
situation is that to a non-technical viewpoint, 'loosely coupled' sounds
like a good way to describe a disorganized system. Moreover, 'tightly
coupled' sounds like a prescription for order and control.

Hmnnn. Interesting. I must remember these nuances of language the next
time I'm customer facing. Proponents of loose coupling, myself included,
need to be cognizant of the disorganizational overtones inherent in the
loose coupling terminology we find so alluring.

Now, lest you feel aggrieved that I have not finished the story about
the loosely coupled IT system in the financial institution, a few
parting facts.

The system in question, is, in fact, very tightly coupled. It's a
minicomputer-based system with PCs acting as green screen terminals.
Whatever vagaries are (to this day!) holding up my transaction have
nothing to do with loose coupling of component pieces.

[1]http://www.google.ie/search?q=SNAFU+situation+normal&hl=en&ie=UTF-8&oe=UTF-8
[2]http://www.technorati.com

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