Abused User Uncooperative business executives and managers who claim "we already told IT what we want" are typically abused users. These folks have been interviewed repeatedly in the past for DW/BI initiatives but have yet to see anything result from their efforts. They are frustrated by past false starts and may even refuse to meet with a requirements team again.
You should proactively determine who was involved and interviewed in earlier DW/BI attempts. Any requirements documentation from the prior project should be reviewed. Unfortunately, documentation is seldom sufficient to take the place of a face-to-face meeting with the business representatives again. When scheduling meetings with these abused users, it's helpful to acknowledge their participation in previous efforts and let them know that you have already reviewed the resulting documentation. The new session can be presented as a validation, rather than as another back-to-the-beginning interview.
Naturally, users will resist rehashing previously covered territory, but they may be more willing to meet if you are focused on understanding current priorities. Finally, this is probably a good time to select an alternative forum for gathering requirements. If interviews were conducted previously, use the earlier requirements documentation as a baseline for a session focused on gather details on changes within their business.
Overbooked User These disengaged business users are simply too busy to meet anytime soon. They may agree to a scheduled time but then not show up or send a substitute in their place. An e-mail message from the program sponsor to all the participants about their importance to the initiative will often nip this disorder in the bud. However, if this is a contagious malady and executive management is unwilling or unable to address the condition, stop before you waste more effort. It's a safe bet that business users who don't have time to meet to share their requirements won't have time to attend education sessions and incorporate new information and analyses into their daily jobs, resulting in a never-ending, uphill struggle for the DW/BI team. Get off this slippery slope before further damage is done. You may be able to locate a more cooperative business partner elsewhere in your organization.
Comatose User These business users respond to your classic, open-ended questions with monosyllabic, one-word responses. Fortunately, this is a relatively rare syndrome. Most often, their apathetic responses are due to external distractions totally unrelated to the DW/BI project. It's sometimes effective to ask these people questions from a more negative perspective. For example, rather than trying to get them to envision life outside the box, these users sometimes find it easier to tell you what's wrong inside the box.
If you have to pry information out of interviewees like this, it's senseless to prolong everyone's pain as these interviews quickly become no fun for anyone involved. Make a valiant attempt, but if it is still not working, abort the interview and schedule a replacement representative if the user is in a critical function or position.