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A Parable

cs.virginia.edu

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Re: A Parable

#41

Post by run4yourlives »

I love this parable, but here's the kicker: The company lost money, and probably, to this day, doesn't understand that it did.

Certain costs are very visible to business leadership. Like the costs of toilets. Others, not so much. Like the time lost in the shunting yard farting around with the cars. Or the costs of people that used someone else's train service because they were pissed at not finding a toilet.

Business, on a whole, is great at optimizing those visible costs, but only the good companies are good at managing those soft costs. All other things being equal, how you manage those soft costs is how you beat your competition.

Re: A Parable

#42

Post by JoeAltmaier »

dbaupp wrote: post #29
mistercow wrote: post #27

Earlier quoted context omitted.

>but I would have been happier if the root cause was fixed. But it was fixed. It just took a clever enough incremental improvement to move back to square one.

It's not quite square one: there's half as many toilets on the train, which probably does save money.

Not sure. Essentially a new class of 'car' was created, twice as long and roughly twice as expensive. If the cost of dealing with the larger cars was non-zero, then maybe it was break-even. Its premature-optimization at its finest I think.

Re: A Parable

#44

Post by dbaupp »

JoeAltmaier wrote: post #42
dbaupp wrote: post #29

Earlier quoted context omitted.

It's not quite square one: there's half as many toilets on the train, which probably does save money.

Not sure. Essentially a new class of 'car' was created, twice as long and roughly twice as expensive. If the cost of dealing with the larger cars was non-zero, then maybe it was break-even. Its premature-optimization at its finest I think.

Yes, but there is half the number of cars in each train, so the doublings cancel out. That said, the overhead of larger cars could still be a significant factor.

Re: A Parable

#45

Post by [deleted] »

anonymouz wrote: post #9
sidcool wrote: post #3

I failed to understand the solution :(

You always keep pairs of carriages, connected like this: +----------------+ +---------------+ | T| | | +----------------+ +---------------+ O O O O where 'T' marks a toilet. You build your train from a bunch of those cars, and now it does not matter how you connect them, you'll always have a toilet within a car's range, plus at worst the additional cost of crossing into the next car (since you can't put the toilet be…

[deleted]

Re: A Parable

#46

Post by shardling »

JoeAltmaier wrote: post #42
dbaupp wrote: post #29

Earlier quoted context omitted.

It's not quite square one: there's half as many toilets on the train, which probably does save money.

Not sure. Essentially a new class of 'car' was created, twice as long and roughly twice as expensive. If the cost of dealing with the larger cars was non-zero, then maybe it was break-even. Its premature-optimization at its finest I think.

Assuming the original cost-cutters decision was correct, it isn't twice as expensive.

Re: A Parable

#47

Post by juan_juarez »

digitalengineer wrote: post #5

Wouldn't it be cheaper to just install the bloody toilets in every train car? Than every car could be everywhere. After all it's just a toilet with a hole.

It's a parable, not a real world situation. It's meant to illustrate how an appropriate abstraction can remove complexity from a problem as requirement get piled on.

Re: A Parable

#48

Post by gojomo »

It may be a symptom of my own possibly-pathological preference for reusable modular design, but I'd want to make tiny toilet-only cars. Borrowing anonymouz's diagram style:

  +---------------+ +-+ +---------------+
  |               | |T| |               |
  +---------------+.+-+.+---------------+
    O            O  O O  O            O
Then all carriage-cars and toilet-cars are…

• reversible

• interchangeable with others of their type

• easily externally identifiable at shunting yards

• able to represent either the original 1:1 carriage:toilet ratio, or the cost-saving 2:1 ratio, or any other ratio that might be desired

• able to represent any desired min-distance/max-distance in carriage-car-lengths to the nearest toilet

• able to be upgraded/serviced independently (including occasional periods of operation outside of usual ratios, as trials or when cars are out-of-service)

Of course the costs of extra couplings (in construction, linear deadspace, and operational overhead), and effects of such unevenly-sized cars on travel characteristics (stability, wear, fuel-economy, etc) might outweigh the explicit flexibility benefits.

But such flexibility is less risky in the abstract and more easily-rewritten world of software where I practice, as opposed to the world of railroad engineering, as practiced (perhaps not coincidentally) by my father's father.

Re: A Parable

#49

Post by digitalengineer »

juan_juarez wrote: post #47
digitalengineer wrote: post #5

Wouldn't it be cheaper to just install the bloody toilets in every train car? Than every car could be everywhere. After all it's just a toilet with a hole.

It's a parable, not a real world situation. It's meant to illustrate how an appropriate abstraction can remove complexity from a problem as requirement get piled on.

As with web/sites, /apps especially if run by inexperienced Project Managers.

Re: A Parable

#50

Post by 3JPLW »

run4yourlives wrote: post #41

I love this parable, but here's the kicker: The company lost money, and probably, to this day, doesn't understand that it did. Certain costs are very visible to business leadership. Like the costs of toilets. Others, not so much. Like the time lost in the shunting yard farting around with the cars. Or the costs of people that used someone else's train service because they were pissed at not finding a toilet. Business…

> All other things being equal, how you manage ______ is how you beat your competition.

What a spectacular tautology. But, yes, you are right. More importantly: It's an easy place to win or lose dollars.

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