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One of the key steps in the analysis stage is ascertaining the user query requirements. Before the data warehouse layout can be designed you need a clear understanding of the queries that are likely to be run. Although there will probably be some canned queries or standard reports that can be identified, it is unlikely that the users will have a clear definition of everything they want.
Even if the users are unusually forthcoming, and can give chapter and verse on their requirements, it is unlikely that this will be the whole story. There may be other users who are to be added later, and there is no guarantee that their queries will be the same as those of the current users.

As the users get used to the data warehouse and its abilities, they may begin to explore data in different ways. Remember, it is the ad hoc nature of a data warehouse that makes it what it is. As the users’ requirements change over time, the data warehouse will evolve, but the database design needs to remain constant. So, when performing the analysis requirements capture, it is vital to gain an understanding of the business, and the business sector it occupies. This is the one constant: even if the business changes, it is unlikely that It will change so radically that it moves business sector. A telco is not likely to become a bank, and an airline is unlikely to become a retail chain. In the unlikely event that such a change does occur, the data warehouse will probably need to be designed again from scratch in any case.