A good question.
It didn’t come up during requirements gathering. Neither did it occur during reiterative development. And it certainly did not come up in user acceptance testing. So why, why, why do users ask for more features and changes AFTER the solution has gone live?
One of the differences between a BI project and any other technical project is that the “Oliver Twist” syndrome is inherently what providing data is all about. When data is first revealed, the human mind then processes the data in an effort to answer questions in the mind. This inadvertently creates more questions and in most cases it will require more data, or a different view of the data to answer.
This sort of requests cannot be captured during any earlier stages just as you can’t find a cure until the disease manifests itself.
What can be done is to analyse the objectives and goals and run a pre-implementation study, where data is queried on an adhoc basis to answer questions. This is best done adhoc so that it can be extremely flexible. This allows the users to plan ahead. After which some of these adhoc reports will probably end up as regular reports and the main bulk of information is used for monitoring and tracking, and fed back for strategy planning purposes.
In any case, don’t be surprised by the “I want more” mentality. Ultimately it is a good thing that cogs in the brains are moving, isn’t it?