Individual relationships join together two or more individual entities. EG Jane Doe manages Fred Smith. . All relationships are bi-directional. Use relationship names that model real world relationships, not system processes. Has , Assigns , Logs , Generates , Processes , Stores and so on are bad relationship names if they refer to internal system processes.
Relationships can have attributes.
If something is Try and arrange entities and relationships from left to right and top to bottom, to make the diagram easier to read. Avoid recursive relationships where possible. Avoid relationships including more than two entity types where possible. Be alert for fan-traps and chasm traps. If two entities are related then you should be able to read across the diagram and tell unambiguously which is related to which.