Does the business really know what it needs?

So we work day in and day out; when it comes to software, does the business really knows what it needs?

Throughout my experience, no. They might think they know the problem and solution, but the problem is never clear until we are dealing with the nitty-gritty details.

Picture waterfall model. Odds are you wont experience and know the answers until late in the game. You do all the analysis, which in most cases is still business focused, design, and then implementation. You will find you answer somewhere in there.... But again a bit late

Picture agile now. You brake the problem into sub problems. It is an approach to divide and conquer of a project. Answers will start popping up early on because iterations are short and once you are finished with an iteration, it's done. All questioned answered and you jump to the next problem.