That's why, when people ask me to estimate work, I tell them that if they need a hard deadline things will (counterintuitively) take much longer, and try to con

That's why, when people ask me to estimate work, I tell them that if they need a hard deadline things will (counterintuitively) take much longer, and try to convince them that hard deadlines are bullshit. If you want a hard deadline, I have no choice but to allocate a huge amount of buffer time, at least twice the "aggressive" estimate so that if shit doesn't go as planned (which is what usually happens) I don't miss the deadline. And I have to plan for the worst possible kind of excrement hitting the fan, which is not realistic. And then, in spite of that, people are still under more stress, because procrastination being in human nature, hard shit gets done last, and there's more in it that can go wrong. Consider instead shipping stuff incrementally, feature by feature, when features are done, without any hard deadlines. Both the speed of delivery and quality will be improved compared to hard deadline driven development. Plans are worthless. Planning is indispensable.