After dozens of Business Intelligence projects and studying scores more we've only found one instance where the answer was to simply buy an off the shelf tool.  Unfortunately we see too many examples of the tool being the first consideration.  This almost invariably leads to underutilized, poorly or partially implemented systems, missed deadlines, blown budgets, poor data quality, frustrated and skeptical business users.  Start with understanding the business objective and collecting and organizing all the data first.   The intelligence is in the well understood data the tool only helps to present it.  Or put another way the data is the steak and the software tool is just the knife and fork you use to cut up the data into tasty bite size pieces.  The knife and fort are definitely invaluable to the expereince of consuming the steak but hardly a consideration when looking at the menu.