[stymaar]

I totally agree with this statement, but here we're talking about 0.5 year of planning !

Planning is important, and cautiously thinking about your features before diving in can save you weeks later on. But spending 6 month in a tunnel, writing specs you'll spend at least a year to implement, is a huge risk : what if your users only use 30% of the features you designed, and lack a missing feature you didn't plan ? You could have figured it out way sooner have you built something earlier and released it.

Also, your time to market is way slower and you don't risk losing years of work by missing a deadline …

> Damn, now I need to move faster. My app must be ready by the time they close Wunderlist. I expected an eventual closure, but not that soon.

[corobo]

> what if your users only use 30% of the features you designed

Or worse, what if different segments of users only use 30% of different feature sets? See also: Evernote's 5% problem [1]

[1] https://venturebeat.com/2016/01/05/evernotes-5-problem-offer...

[obsurveyor]

> I totally agree with this statement, but here we're talking about 0.5 year of planning !

Yeah but that's not necessarily in man-years. Maybe he worked on it an hour or two a day. Now we're talking around two man-weeks of planning.

[roel_v]

Well you'll only find out which 30% after building it, regardless of whether you have a spec or not. You can write a.spec for an mvp too.