Waterfall can work great when: 1/ the focus is long-term both in terms of knowing that she company can take a few years to get the thing live but also that it will be around for many more years, 2/ the people writing the spec and the code are largely the same people.

Agile was really pushing to make sure companies could get software live before they died (number 1) and to remedy the anti-pattern that appeared with number 2 where non-technical business people would write the (half-assed) spec and then technical people would be expected do the monkey work of implementing it.

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aglavine 2 hours ago | parent | next [-]

No.

Agile core is the feedback loop. I can't believe people still don't get it. Feedback from reality is always faster than guessing on the air.

Waterfall is never great. The only time when you need something else than Agile is when lives are at stake, you need there formal specifications and rigorous testing.

SDD allows better output than traditional programming. It is similar to waterfall in the sense that the model helps you to write design docs in hours instead of days and take more into account as a result. But the feedback loop is there and it is still the key part in the process.

	▲	jll29 an hour ago \| parent \| next [-]
		> The only time when you need something else than Agile is when lives are at stake, you need there formal specifications and rigorous testing. Lives are always at stake, given that we use software everywhere, and often in unintended ways, even outside its spec (isn't that a definition of a "hack"?). People think of medical appliance software, space/air traffic software, defense systems or real-time embedded systems as the only environments where "lives are stake", but actually, in subtle ways, a violation of user expectancy (in some software companies, UX issues count as serious bugs) in a Word processor, Web browser or the sort command can kill a human. Two real-life examples: (1) a few years ago, a Chinese factory worker was killed by a robot. It was not in the spec that a human could ever walk in the robot's path (the first attested example of "AI" killing a human that I found at the time). This was way before deep larning entered the stage, and the factory was a closed and fully automated environment. (2) Also a few years back, the Dutch software for social benefits management screwed up, and thousands of families just did not get pay out any money at all for an extended period. Allegedly, this led to starvations (I don't have details - but if any Dutch read this, please share), and eventually a whole Dutch government was forced to resign over the scandal.
	▲	keyle an hour ago \| parent \| prev [-]
		I've live through both eras... Agile, hardly any planning, write 3 times. Waterfall, weeks of planning, write 3 times anyway. The point is, people don't know what they want or are asking for, until it's in front of them. No system is perfect, but waterfall leads to bigger disasters.

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user3939382 2 hours ago | parent | prev [-]

I spent my career building software for executives that wanted to know exactly what they were going to get and when because they have budgets and deadlines i.e. the real world.

Mostly I’ve seen agile as, let’s do the same thing 3x we could have done once if we spent time on specs. The key phrase here is “requirements analysis” and if you’re not good at it either your software sucks or you’re going to iterate needlessly and waste massive time including on bad architecture. You don’t iterate the foundation of a house.

I see scenarios where Agile makes sense (scoped, in house software, skunk works) but just like cloud, jwts, and several other things making it default is often a huge waste of $ for problems you/most don’t have.

Talk to the stakeholders. Write the specs. Analyze. Then build. “Waterfall” became like a dirty word. Just because megacorps flubbed it doesn’t mean you switch to flying blind.

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catdog 2 hours ago | parent | next [-]

> The key phrase here is “requirements analysis” and if you’re not good at it either your software sucks or you’re going to iterate needlessly and waste massive time including on bad architecture. You don’t iterate the foundation of a house.

This depends heavily on the kind of problem you are trying to solve. In a lot of cases requirements are not fixed but evolve over time, either reacting to changes in the real word environment or by just realizing things which are nice in theory are not working out in practice.

You don’t iterate the foundation of a house because we have done it enough times and also the environment the house exists in (geography, climate, ...) is usually not expected to change much. If that were the case we would certainly build houses differently than we usually do.

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Mawr an hour ago | parent | prev [-]

> making it default is often a huge waste of $ for problems you/most don’t have.

It's the opposite — knowing the exact spec of your program up front is vanishingly rare, probably <1% of all projects. Usually you have no clue what you're doing, just a vague goal. The only way to find out what to build is to build something, toss it over to the users and see what happens.

No developer or, dear god, "stakeholder" can possibly know what the users need. Asking the users up front is better, but still doesn't help much — they don't know what they want either.

No plan survives first contact with the enemy and there's no substitute for testing — reality is far too complex for you to be able to model it up front.

> You don’t iterate the foundation of a house.

You do, actually. Or rather, we have — over thousands of years we've iterated and written up what we've learned so that nobody has to iterate from scratch for every new house anymore. It's just that our physics, environment, and requirements for "a house" doesn't change constantly, like it does for software and we've had thousands of years to perfect the craft, not some 50 years.

Also, civil engineers mess up in exactly the same ways. Who needs testing? [1]. Who needs to iterate as they're building? [2].

[1]: https://youtu.be/jxNM4DGBRMU?t=397

[2]: https://youtu.be/jxNM4DGBRMU?t=837

	▲	embedding-shape an hour ago \| parent [-]
		> knowing the exact spec of your program up front is vanishingly rare, probably <1% of all projects I don't have anything useful to add, but both of you speak and write with conviction from your own experience and perspective yet to refuse that the situation might be different from others. "Software engineering" is a really broad field, some people can spend their whole life working on projects where everything is known up front, others the straight opposite. Kind of feel like you both need to be clearer up front about your context and where you're coming from, otherwise you're probably both right, but just in your own contexts.