

A Tale of Two Bridges - raldi
http://unprotocols.org/blog:16?

======
choffstein
Robert Martin (<https://en.wikipedia.org/wiki/Robert_Cecil_Martin>) once
tweeted (@unclebobmartin):

"When designs are cheaper than builds, e.g. a skyscraper or a bridge, big up
front design makes good sense. But when builds are cheaper than designs, e.g.
software or oil painting, short and iterative design and build steps are
best."

I couldn't agree with that more.

I work in an industry where builds are not cheap and iteration after launch is
nearly impossible. You better believe we have a very, very long design cycle.

~~~
scrumper
This is why I like coming here. I'd never thought of the tradeoff in that way
before reading that quote, yet it makes perfect sense.

(I'm not arguing with your point at all, but of course there's software... and
then there's software. Building might be cheap for both, but cost of
deployment could be entirely different. Spacecraft control, microcode in an
appliance, even certain classes of enterprise software all benefit from big
up-front design because it's so expensive to patch later.)

------
Stratoscope
Forgive a shameless plug for a dear friend, but Harmon Parker builds
footbridges in the back country around Kenya. His bridges bring people
together and save lives:

<http://www.bridgingthegapafrica.org/>

What he does is not too different from the rope guy in the parable. He doesn't
come in with a big team and a grand plan. He goes out and gets to know the
people and finds out from them where they have dangerous crossings and what
they need, and they build a bridge with him.

Harmon has the engineering know-how to make it safe, and the local people have
knowledge he never could assume. When it's done, it's their bridge and they
know how to maintain it: the people who use the bridge have been involved from
the beginning.

~~~
ChuckMcM
That is an awesome video.

~~~
Cobbler
I agree! Good to see humanity at their best.

------
chasing
I, too, can write vague parables to support just about any point.

And what is the point? That it's always better to let the grassroots develop
software? Like so many other things in this world: It's Just Not That Simple.

~~~
sxcurry
Agree - this type of parable may be suitable for small children, but if you
think about it, it has zero information content, and no applicability to the
real world.

I'd much rather read a real story about a real bridge or two - that's what I
come to HN for.

~~~
raldi
Real world version: Google Wave is bridge #1.

Edit: The CueCat is an even better example!

Meanwhile, the transition of Amazon from bookseller to everything-seller to
hardware maker to cloud company is a good example of a real-world Bridge #2
story. Or the transition of Justin.tv into Twitch.

~~~
yen223
The first iPhone is also bridge #1. An overly-designed gizmo that no one
needed at the time.

Hence its massive failure.

~~~
raldi
You're attacking a strawman. Nobody claimed Bridge 1 is always the wrong
choice.

~~~
yen223
Sorry for the snark. I'm merely pointing out that the real world is a lot more
nuanced than "Big design bad! Agile good!"

------
benihana
So the moral of the story is...

cross that bridge when you get to it.

Ha-ha! GET IT? No seriously, though. That's the lesson. Build for actual need
now, not something you think you might need in the future.

------
drcube
I think the moral is to pave over the desire path[1] and iterate with user
feedback, rather than doing the big design up front and finding out nobody
wants to use it after the money is already sunk.

[1]<http://en.wikipedia.org/wiki/Desire_lines>

------
nealabq
The lesson is the first bridge would have been an unqualified success if only
they had conducted usability studies and A/B testing and gathered feedback
from community-oriented focus groups and practiced just-in-time lean-agile
bridge-driven design concepts.

And applied for 6000 patents.

~~~
tazzy531
First paragraph is optional.

------
mistercow
>Just a rope, tied to two trees. There were two villages, one at each side. At
first, people pulled packages across that rope with a pulley and string.

I'm trying to visualize this, and it's not making any sense to me. I searched
around to see if any such system is commonly used, and the closest I can find
is a hauling line, which requires a second length of rope, at least long
enough to span the gorge twice, which is hooked to the original rope via a
carabiner and anchored at both sides. But there's no pulley involved with that
(although if you wanted to over-engineer it, I guess you could use one instead
of the carabiner).

So is this an actual thing that people do, or am I reading too much into this
parable?

~~~
raldi
I think by "pulley", he meant "zipline". Just something which can ride along
the rope.

------
edw519
Enterprise ending:

The Big 5 auditors refuse to certify the suspension bridge because in their
opinion, it doesn't satisfy GAAP & SOX.

$10 million is paid to the Big 5 auditors for a program of education and
documentation to convince everyone to use the "best of breed" bridge.

The suspension bridge is sunsetted.

It's so difficult to use the enterprise bridge that people don't bother.
Eventually they move to another valley.

The town dies and its assets are sold for 10 cents on the dollar. Management
blames "market conditions".

~~~
notatoad
I love when metaphors get stretched beyond their breaking point.

~~~
wam
Well, to be fair, the load rating on this metaphor is only 10 comments +/- 2.

------
far_at_makerbot
I think the lesson is that vague fictional parables to support your worldview
are a better way to work than real stories or facts.

~~~
qu4z-2
I'm at all convinced that this would be any truer had it actually happened.

------
praptak
See also the recent Death Star Design Pattern by K. Kovacs:
<http://kkovacs.eu/the-death-star-design-pattern>

The first bridge was an example of this.

------
joss82
Can you possibly REPLACE stone by steel in a bridge without destroying it and
building it back again?

Doesn't sound plausible to me...

In the real world, when Engineer 2 needs a steel bridge to replace the stone
one, he asks Engineer 1.

That would be the condition required for Engineer 1 to build her fancy bridge.
If market research had been done properly beforehand, of course.

------
apdinin
Legal Disclaimer: Don't forget about the possibility of a child falling off
the rope bridge because of poor construction and the builder getting charged
with involuntary manslaughter as a result of product negligence.

~~~
jtms
you just HAD to go and get the lawyers involved didn't ya?

------
udioron
"In most parts of the world, when a bridge is needed it is built from wood,
steel or concrete. But in Cherrapunji in northeastern India, the locals are
much more patient. They simply coax nearby trees to grow into natural bridges.
The process takes many years, but the result is completely natural,
surprisingly strong, and looks like something out of a wonderful fantasy
world..."

From: [http://webecoist.momtastic.com/2009/10/21/bridge-to-
nature-a...](http://webecoist.momtastic.com/2009/10/21/bridge-to-nature-
amazing-indian-living-root-bridges/)

------
ww520
The point of the tale is to hire the 2nd engineer on the cheap to find out
where people cross the river, then hire the 1st one to build the real thing.

~~~
raldi
What if it turns out that there's only enough demand to support a wooden
bridge? If you went right from the rope to the superbridge, you've wasted an
unbelievable amount of effort.

------
olalonde
Reminds me a quote from pg: "Don't try to construct the future like a
building, because your current blueprint is almost certainly mistaken. Start
with something you know works, and when you expand, expand westward."
<http://paulgraham.com/ambitious.html>

------
jtms
I have heard a very similar tale used to describe the inefficiencies of a
centrally planned economy vs free market.

------
frozenport
Needs more GNU/Bridge

