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I thought waterfall was a strawman too, until I read The Checklist Manifesto and started learning more about other industries. For example, large-scale constru

by alabut 15y ago

I thought waterfall was a strawman too, until I read The Checklist Manifesto and started learning more about other industries. For example, large-scale construction projects like skyscrapers are run by gantt charts and committees, which sounds unbelievable and like a disaster waiting to happen. It's like the opposite of every startup I've worked at in the last 4 years. Except it actually works and they keep the everything running smoothly through: * (at the top level) real time adjustments to huge room-filling charts that shown all the dependencies. * (at the grunt level in the trenches) an abundant use of checklists to keep work mistake-free and to avoid groups stepping on each other. * (at all levels) constant and real time communication. Lots of it. So yeah, I think it's hard to write off waterfall as both ineffective and non-existent if a large industry uses it to such a degree.

wpietri 15y ago
Large-scale construction projects are also notorious for delays and cost overruns, so I wouldn't make too much of that. Even granting your point, though, that doesn't tell us much about software. Nobody expects to start a building as a small house and work it up to something the size of the Pentagon. You can't automatically replace every screw in a building in minutes. Buildings aren't made out of words, and they don't have requirements that change continuously. Buildings aren't expected to respond quickly to competitor's new amenities. The construction of buildings is not 100% automatable with modern technology. So I wouldn't be too hasty in suggesting that the Waterfall approach is made more plausible by a similar-sounding process being used in an entirely different industry. And honestly, real buildings aren't even much like what you're imagining. Stewart Brand's book "How Buildings Learn" examines actual buildings and how they adapt and change in ways very different than what people with GANTT charts think should happen.
jerf 15y ago
Waterfall has no such history in the software domain. Analogizing software to construction has a long and worthless history, and it has failed to produce one actionable insight that I'm aware of. (It has produced some really dangerous pronouncements about how software engineering should be done, of the kind that you can crash and wreck a company on, though, so there's that.) The problem is that construction has a completely, radically different cost model than software. If they could possible throw up one building today, tweak it, and throw up another tomorrow, they'd go iterative too. Instead, they have horrifying implementation costs that have no analogy to software; if Waterfall "works" for them it is only because they have no other choices. That's hardly a ringing endorsement, as wpietri observes.

by alabut 15y ago

wpietri 15y ago

Large-scale construction projects are also notorious for delays and cost overruns, so I wouldn't make too much of that. Even granting your point, though, that doesn't tell us much about software. Nobody expects to start a building as a small house and work it up to something the size of the Pentagon. You can't automatically replace every screw in a building in minutes. Buildings aren't made out of words, and they don't have requirements that change continuously. Buildings aren't expected to respond quickly to competitor's new amenities. The construction of buildings is not 100% automatable with modern technology. So I wouldn't be too hasty in suggesting that the Waterfall approach is made more plausible by a similar-sounding process being used in an entirely different industry. And honestly, real buildings aren't even much like what you're imagining. Stewart Brand's book "How Buildings Learn" examines actual buildings and how they adapt and change in ways very different than what people with GANTT charts think should happen.

jerf 15y ago

Waterfall has no such history in the software domain. Analogizing software to construction has a long and worthless history, and it has failed to produce one actionable insight that I'm aware of. (It has produced some really dangerous pronouncements about how software engineering should be done, of the kind that you can crash and wreck a company on, though, so there's that.) The problem is that construction has a completely, radically different cost model than software. If they could possible throw up one building today, tweak it, and throw up another tomorrow, they'd go iterative too. Instead, they have horrifying implementation costs that have no analogy to software; if Waterfall "works" for them it is only because they have no other choices. That's hardly a ringing endorsement, as wpietri observes.