A Manager's Guide to Data Warehousing

Chapter 6. Providing Business Requirements

Now that the project is set up, it is time to get started on the work. The next step of the project is to collect requirements. The intent is the same as with any other system design project: to ensure that the ultimate system serves the intended purpose. However, the requirements needed to design a data warehouse are distinctly different from those for operational systems. Operational system requirements are very specific to ensure that the business function or transaction is completed accurately. For example, a concrete set of criteria must be met to complete an online product purchase. Data warehouse requirements are often general and much more fluid. In a company, there may be a need to produce a report of the top twenty-five corporate customers and their year-to-date purchases, but tomorrow the hot topic needing attention may be identifying bottlenecks in the distribution channel. These differences create challenges for projects that use the same approach for a data warehouse project as for an operational system project.

This can lead to a communication gap between business and technical staff members when trying to gather requirements for a data warehouse. The systems community feels like the business does not know what they want because when asked, "What report do you want first?" they get a different answer each time. Likewise, there is frustration on the part of the business because requests are made, but IT does not deliver what ...