An entity-relationship diagram shows the structure of data within a system or domain.
It represents entities, attributes, and relationships. Moreover, it can show primary keys and cardinalities. Therefore, stakeholders can understand how important information connects.
Common notations include Chen notation and crow’s-foot notation. For example, rectangles may represent entities. Meanwhile, lines and symbols describe relationships and their cardinalities.
Teams use an entity-relationship diagram to define conceptual data structures. It focuses on static information. In contrast, process and activity diagrams describe behavior and control flow.
At the requirements level, the model should avoid unnecessary database details. Instead, it should describe relevant business objects, data rules, and relationships.
Teams should use consistent terms and validate the model with domain experts. In addition, they can link entities to requirements, use cases, and interfaces.
Clear data models support requirements analysis, data quality, interface definition, and system design.
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