This section provides information about the entities and their relationships to each other. The number of entities may change as they are created, so a consultant can introduce or reuse entities after discussing this with their team. An FDD must include an updated ER diagram; so, if there are any changes in the structure, the business analyst or functional consultant needs to update the FDD. The following diagram shows an example of an ER diagram:

This ER diagram represents out-of-the-box entities and custom entities that we are going to mainly use for our HIMBAP Auto Service Center customer. As you can see, we are going to reuse some of the existing entities, as well as creating some custom entities.