I always liked the One Minute Manager's take on this. The idea is that everyone should be able to state their current goals and progress within a minute. And

I always liked the One Minute Manager's take on this. The idea is that everyone should be able to state their current goals and progress within a minute. And that's how long your meeting with your manager should be. If you can't do that, it's too complicated. Other meetings, like brain storms with mutually trusting participants, can of course be longer.