More from Lean Software Development

[T]he principle deliver as fast as possible complements decide as late as possible. The faster you can deliver, the longer you csn dely decisions. For example, if you can make a software change in a wekk, then you do not have to decide exactly what you are going to do until a week before the change is needed. On the other hand, if it takes you a month to make the change, then you have to decide on the details on the change a whole month before it is due. Rapid delivery is an options-friendly approach to software development. It lets you keep your options open until you havfe reduced uncertainty and can make more informed, facty-based decisions.

From Lean Software Development.