Re: OOP/OOD Philosophy

krasicki wrote:


Les Cargill wrote:

krasicki wrote:

Michael Feathers wrote:


krasicki wrote:


Daniel Parker wrote:



"krasicki" <Krasicki@xxxxxxxxx> wrote in message
news:1120611204.476214.162240@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx




Look, OOD is about designing theoretical systems ... 

Just out of curiosity, what theory?

-- Daniel 


Well Daniel,

Not all systems consist of a web front end that accesses data from a
well-established database though many do.

OOD, depending on the tools and techniques you use, allows system
designers to model potential solutions in numerous ways.  If this
tradeoff is made here, this benefit is forthcoming there and so on.
Design is about applying recombinant ideas to solving problems.

Systems are developed to solve problems in effective ways.  Systems are
not developed for the sake of software or to gratify the provincial and
esoteric ego needs of the employees charged with getting the system
implemented.

I'll give you a good example.  A Hilton was just built in Hartford and
the building went up fast to meet the deadline of the new convention
center being built next door.  All federal guidelines were applied.

So come inspection day, Connecticut's inspectors applied Connecticut
building statutes to the inspection and the building failed!  Now one
could say that the building was built fast, saved money, and looks real
good and boy were the builders proud of it.  Let's call this process
agile.

So sixteen of the rooms were incorrectly built for handicapped access,
an error of three inches per room.  Where to get three inches?  Push
the rooms into the hall and the hall fails.  You can see how this goes.

Another example.  A Hospital builds a new wing onto an existing
structure and these days new hospital wings look like fancy hotels.
Everything is immaculate, grand fascades, fancy everything.  The
hospital wing opens without a hitch.

The first bed is rolled down the hall, the elevator button is pushed,
the door opens, the bed pushed into the elevetor as far as it can go,
but the bed still doesn't fit.  Wrong sized elevator.



It's pretty amazing to me that you find anything in common with Agile in
these scenarios.  They all sound like cases were there was no feedback
or testing.  Sounds more like plan-driven development to me.



Au contraire.  The bricks all passed unit tests.  As did the cement,
steel, and so on.  And the plans all had feedback.


Not the right feedback. It's a failure of requirements capture,
pure and simple. No methodology nor any other thing, other
than collecting all the relevant requirements and checklisting
them, would have made a bit of difference.



I will infer that you're saying that More planning anfd preparation
time might have comprehensively accumulated and accounted for these
missing design considerations.  In other words a hieavier weight
methodology could have avoided the headaches - all things being equal.


Not at all - I'm just saying thst missing the point is
missing the point. If the elevator width doesn't
meet spec, it simply doesn't.

How that's acheived isn't on the table. I dunno
the people, dunno the domain.

Heavier weight process might obscure the requirement.

It's ultimately an anthropology problem.


And the customer
surely showed up with a glowing smile watching the obvious progress.
And progress happened every day.

The elevator worked fine.  Up.  Down.  Ring, ring.  All positive
feedback.

The workers sweated.  The execs wore suits and went golfing.



These are true stories.  Shouldn't all of the architects of these
buildings have expected change to happen as well.  Same with the
builders.  maybe build with everything loose so that it can be
reassembled when the next minor detail arises?  Aren't we being told
this is the way things work?


Well, the fact is software is malleable.  In fact it is too malleable.
It isn't hard to change software at all.  All you have to do is type a
couple of characters in any program and you can break it.  Because that
is the way that software is, we need tests to give it backbone.



It's not that malleable.  Once in production software is very hard to
change for all kinds of political reasons.


It shouldn't go into production with defects that are gonna
cost people money, at least without an enforceable plan
to get the defects out, upfront.

Once in production, somebody has to make the decisions of
when, how and why to deploy upgrades.



Well, my point is that if something goes through the XP methodology
with all of the hot air and hubris that one has performed a bazillion
tests on it already but defects still exist, who will know and how
could they prove it.


No process can guarantee any result. You really need respectful
interaction between subject matter experts and the implementors.

If the tests are wrong, they're wrong. Fix 'em.

Would any of us argue for long with these people?  I lose heart just
trying to get a straight answer out of them in something as
straightforward as a newsgroup.  Haven't you heard,  XP is absolutely
right because they've tested everything every which way.


I used XP , once. It contributed zero defects in five years*. This
was no more absolutely right than anything else - it modelled
a well-known system with loads of test data.

*sampling limit, in this case.

Once in commercial production, software that is mission critical is not
easily changed because, as someone said elsewhere, tweaking the wrong
bit could cause system calamities.  Reintroducing code in these
enevironments could take six months to a year of expensive rework or
total shutdown.


Then you have to get it right the first time. That costs
money, you know. If it costs more than you have,
try to keep the drawing to inside straights to a minimum.

 It's no longer a question of tweaking code but
questioning all assumptions.  With BDUF, you can isolate the problem
and hypothetically run the system without software trying to understand
the overall implications.



That sounds heartbreaking. It sounds like fighting a war on two fronts. Why no alliances, then?

In fact a big problem for architects and designers is having
programmers undermine design activity with too much dog and pony
prototyping.


How is that possible? Other than time being wasted, prototyping
is harmless. Prototypes should not even be attempted until
there's a specific question or suite of questions they are
to answer. If it's a sandboxed protpype, just to let the
programmers play, then chunk it, or put it away. You
still need specific deliverables from the prototyping.



Prototyping is political dynamite in many organizations.  Software
designers and architects are usually discussing issues that are not
near and dear to the hearts of the local application domain princess
who wants to have someone to talk to.  Enter, any number of local
characters who begin prototyping their idea of what should happen.
Before long the architects and designers are entangled in favorite
color discussions and presentation fashion shows.


But that's a Big Man problem. Who is the champion
for this? Who's the Boss?

Surely methodology cannot solve organizational
psychology problems at this level.

Add to this mix, any number of programmers who believe they know better
than the people always talking about abstract ideas and you enter the
realm of random, esoteric, and uncontrollable development.



That's where the Four W's come in - Who, What, Why and When.

Bad ideas become adopted before any discussion of the
larger picture can be formulated.


Then they have to get rooted out and killed, or at least
triaged and weighed for "badness". Bad ideas that don't get
shot are a sign of complacency, not methodology.



There is no budget to root things out and bad software is often
sponsored internally by incompetent people who control your paycheck.
XP adds authenticity to the problems involved.


Incompetent people are just competent people who
haven't figured it out yet. Clue - one mechanism
of competence is being transparent.

Because software development is so tightly coupled to the individuals,
it is no longer a matter of correcting or eliminating problematic code.
 The XP crowd has a vociferous ego stake in what's being done.  They've
got stories and tests and feedback loops that will insist it's there
right.  They all feel good about it.  And there is no impartial design
document you can point to to say otherwise because the whole ball of
wax is personal, intimate, immediate, and a treadmill of exhaustion for
everyone involved.


You don't need a methodology, you need a guillotine! Actually,
you need leadership, but I understand....



Of course you need tests.  We aren't a bunch of ninnies here.



Even carpenters measure before they cut.  Yet, in computer science we
are being told that we should operate as though we are all alchoholics
and take things one day at a time.


The problem is: misunderstanding the material you are working with.
Code is not wood or concrete.



But spent resources are.  Nobody fixes anything for free.  And bad code
applied to millions of daily transactions can cost companies or
customers lots and lots of money when wrong.


So somebody has to do a cost-benefeit analysis of when to do what.
Good code isn't free, either. This is logistics, not particularly
even software logistics.



The key term is "has to".



Exactly. But in the absence of accountability, all things
are possible.


Testing is tricky stuff and complex logic errors don't get discussed
when daily iterations are the norm because there is no time.

Design and OOD are not code or code design.


You can't fix culture with tools, in other words. Mostly, yes :)


Thanks Les.  Arguing XP is as thankless a task as I've ever
encountered.  The proponents swarm on critics like hornets so try to
avoid this stuff more often than not.  I sincerely was trying to give
the OP a fair assessment of what's out there but this quagmire blocks
all light from shining through.


But isn't it amazing what can be accomplished in the face of
those sorts of odds? People *are* rational, once you do
the heavy lifting for 'em. After all, that's why you're
there.

Fighting a lost cause to a draw is about as good
as it gets on this planet. And sometimes, you are the
windshield and not the bug.

I don't mean to appear arrogant; far from it. But
nobody say it s'posed to be easy.

--
Les Cargill
.