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Conforms-relation

Figure 3.4 shows that for each pair of adjacent component type layers there are two relations: First there is an inheritance structure, where lower layers inherit from upper layers, second there are conforms-relations. The inheritance structure implies, that properties and the amount of information for lower layers of component types increases. Component types of lower layers always provide more information than upper layers. The latter relation defines conditions that must be matched so that two component type instances are in a sub-type / super-type relation.

The conforms-relation is of particular interest in this section. To distinguish the conforms-relation between provided type and complete type is called conforms, the one between complete type and implementation type is called impl-conforms.

To sum up: the inheritance structure is part of the concepts of the meta-model, whereas the conforms-relations describe instance relations.

For example every complete type has a provided type it conforms to - the provided type it describes itself. Every implementation type is a complete type and a provides type. Further more every complete type conforms to itself and every implementation type conforms and impl-conforms to itself.

Example 3.3 (Refinement process)   If there is an provided type $ P$, a complete type $ C$ and an implementation type $ I$, where $ C$ conforms to $ P$ and $ I$ impl-conforms to $ P$, $ P$, $ I$, and $ C$ are likely part of a refinement process. One might have started designing $ P$, then later on added mandatory requires interfaces expressed in $ C$, and then added some SEFF-information. This is a typical top-down development process of a component.



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Next: Conforms-relation between Complete Type Up: Relations between Component Type Previous: Visualization   Contents   Index
Snowball 2007-03-16