Building a data model

There is a process to go through which will be described in more detail in the next section:
1. identify candidate entities

2. select a central candidate entity

3. define the primary key

4. work through the rest of the candidate entities:

• consider whether it is in scope
• define the primary key
• define the relationship(s) between the candidate entity and all other candidate entities on the diagram
• add description entities as needed
• fully express the cardinality of the relationship(s)
• name the relationship(s)

5. for each entity on the diagram

• define the remaining attributes
• define the non-functional requirements

6. review and refine
7. Advanced data modelling concepts

• Super-types and sub-types
• Hierarchies
• Exclusive relationships
• 3rd normal form