Some people cannot understand why data requirements are important. There are a lot of Business Analysts who say they have never collected data requirements and do not understand why they should. Here is one small example from my experience. I was doing some business analysis consulting at a state agency that was just beginning to use the RUP methodology and the Business Analysts were busy using use cases to document most of their requirements.
One story I heard when I first arrived on my assignment was that they had written all their uses cases in great detail and had an approved prototype. The developers had done their testing, and they were really trying to rush to get everything ready to go to production when someone discovered a big problem that delayed the project for several months. During User Acceptance Testing, it was discovered that new data was now being collected from the users of this application but this new information had no where to go. The database did not know about the new data requirements. No one had collected the data requirements for the application – only the use cases. The data could not be stored. No one had modeled anything for the DBA.
To keep the project from being delayed, the IT group suggested that the business keep track of the data manually. Another option they suggested was that they could just create notes in the application with the new information until such time that the data requirements could be collected and the data models designed. The business folks were livid that such a silly mistake could be made. The project was delayed and no one was satisfied. Do you have any stories about why capturing and modeling data requirements is important for requirements elicitation?