OmniGraffle for Mac. Balsamiq. Entity Modeling. In the past two issues, I've discussed data modeling, explaining how to gather requirements and model the business processes of a fictitious publishing company.
Now let's look at the entity model, which is the third step in the data-modeling process. I'll create two types of entity relationship diagrams (ERDs), explain how each connects to the data-flow diagram (DFD) of the process model, and show how they provide a more detailed view of the company's data requirements. A model is a representation of reality. The entity model (also called a conceptual model) displays the data a business collects and uses.