Video:

Estimating Durations

Have you ever been given a task to do, and had to estimate how long it’s going to take – its duration – and you haven’t a clue? It’s a brand new task, you’ve no idea how long it’s going to take, it’s quite complex, lots of different elements in it, but you’ve got to come up, somehow, with an estimate.

So I’d like you to think of that kind of situation, where you’ve got a task, you’ve got to estimate how long it’s going to take, and you don’t know. So I’d like you to think of a task that fits that description. Pause this video if you need to, have a think, come back when you’re ready. OK – so you’ve got a task in mind, and you don’t know how long it’s going to take. Here’s a simple idea for finding an estimate. It seems a bit crazy, but it works for a lot of people.

So here we go. I’m going to offer you these two hands, and each hand represents an extreme measure of time. This one represents seconds. This one represents years. So I’m going to ask you, in terms of the task you’re thinking about – do you think that the time it will take is better measured in seconds, or years? The chances are it’s going to be neither of those, but come on, have a shot – would you rather measure in seconds or years? Let’s say you’re going to choose years. OK. I’ll move to the next smallest unit: minutes. Minutes or years? Years. Next unit: hours or years? Years. Days or years? Years. Weeks or years? Weeks. Weeks or months? I’ve move down from years to the next unit level, which is months. Weeks or months? Weeks. Well, now it would be 4 weeks at the maximum, otherwise it would be months. So you’ve said weeks, so it’s either 1 week or 4 weeks – otherwise you’d be measuring in months. 1 week or 4 weeks? Closer to 4. OK – 2 weeks to 4 weeks? Still closer to 4. OK – there’s your estimate: between 3 and 4 weeks. That’s it.