Pop The Why Stack

I think one of the most important idea's in lean/agile development is the attention devoted to only doing work where it provides value. One of the best expressions of this I've seen is on Cucumber's wiki page. Basically it says...

Before doing something pop the why stack recursively until you end up with one of the following business values; protect revenue, increase revenue or manage cost.

I think that's a powerful razor to cut things with!