We will now introduce a novel idea for determining and recording information requirements for a data warehouse. This concept helps us to give a concrete form to the various insights, nebulous thoughts, and opinions expressed during the process of collecting requirements. The information packages, put together while collecting requirements, are very useful for taking the development of the data warehouse to the next phases.

5.3.1. Requirements Not Fully Determinate

As we have discussed, the users are unable to describe fully what they expect to see in the data warehouse. You are unable to get a handle on what pieces of information you want to keep in the data warehouse. You are unsure of the usage patterns. You cannot determine how each class of users will use the new system. So, when requirements cannot be fully determined, we need a new and innovative concept to gather and record the requirements. The traditional methods applicable to operational systems are not adequate in this context. We cannot start with the functions, screens, and reports. We cannot begin with the data structures. We have noted that the users tend to think in terms of business dimensions and analyze measurements along such business dimensions. This is a significant observation and can form the very basis for gathering information.

The new methodology for determining requirements for a data warehouse system is based on business dimensions. It flows out of the need ...

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