Understand why business requirements are the driving force
Discuss how requirements drive every development phase
Specifically learn how requirements influence data design
Review the impact of requirements on architecture
Note the special considerations for ETL and metadata
Examine how requirements shape information delivery
In the previous chapter, we discussed the requirements definition phase in detail. You learned that gathering requirements for a data warehouse is not the same as defining the requirements for an operational system. We arrived at a new way of creating information packages to express the requirements. Finally, we put everything together and produced the requirements definition document.
When you design and develop any system, it is obvious that the system must exactly reflect what the users need to perform their business processes. They should have the proper GUI screens, the system must have the correct logic to perform the functions, and the users must receive the required output screens and reports. Requirements definition guides the whole process of system design and development.
What about the requirements definition for a data warehouse? If accurate requirements definition is important for any operational system, it is many times more important for a data warehouse. Why? The data warehouse environment is an information delivery system where the users themselves will access the data warehouse repository and create their own outputs. ...