In this chapter you present and carefully explain the solution’s information model, and the information entities it consists of (information viewpoint).
I usually draw an UML class diagram to Illustrate the information model:
The model must show all significant information types that flow in the business domain in which the solution will function.
Don’t fall for the temptation to think in terms of databases, tables and records. I always place those details in the components chapter.
Stick to technology-neutral business terminology. Think of the information model as an extension of the glossary. The model enriches the term definitions by illustrating how they are related, and which entities control the lifecycle of other entities.
Getting this right early – and really achieving consensus among SMEs, BAs, developers in the project team and any external teams whos systems you’re going to integrate with, saves time in the long run.