Diagramming Conventions
 

Supertypes and Subtypes

Certain groups of classes share common properties and have their own unique properties. For example, GP PRACTICE and HEALTH AUTHORITY have an identifier code, name and address etc., as well as having their own unique properties.

The common properties are grouped into a 'supertype', for GP PRACTICE and HEALTH AUTHORITY the 'supertype' is ORGANISATION. GP PRACTICE and HEALTH AUTHORITY are then classed as 'subtypes' of ORGANISATION and as such inherit the properties of the 'supertype' as well as having their own properties.

An example of a 'supertypes' and 'subtypes' in diagrams is given below:

UML Diagramming Convention showing a Supertype and two of the Supertypes Subtypes. The Supertype Class is ORGANISATION (in this example) and the two Subtypes are the Classes GP PRACTICE and HEALTH AUTHORITY.