Data modelling

In information system design, data modelling refers to the analysis and design of the information in the system, concentrating on the logical entities and the logical dependencies between these entities.

In the early phases of a software development project, emphasis will be on the design of a conceptual data model. This can be detailed into a logical data model sometimes called a functional data model. In later stages, this model may be translated into physical data model.

Several techniques have been developed for the design of a data models. Most noticeable are:

• Bachman diagrams
• Entity-Relationship Diagrams (Chen)
• Entity-Relationship Diagrams (Martin)
• ORM