TABLE OF CONTENTS This section introduces a diagram that is completely new to UML version 2.0 and is known as the 'composite structure diagram'. The composite structure diagram realises a structural aspect of the model and has two distinct purposes:
Compositions and aggregations may be represented within the boundaries of a 'Part' without the need to show the aggregation or composition relationships explicitly. This means that an emphasis may be put on the logical relationships between elements of the composition, rather than the structural breakdown itself. This adds a great deal of value, as it forces the modeller to think about the logical relationship between elements, rather than simply which classes are part of which other classes.
Collaborations may be identified in the composite structure diagram. Collaborations in UML version 2.0 are static structures that simply identify that there is some sort of communication between one or more elements within the model. This idea is slightly different from the concept of a collaboration in UML version 1.x. In the previous incarnations of the UML, there was a diagram known as the 'collaboration diagram' (now known as the 'communication diagram') that realised a behavioural aspect of the model, so this slight change in the usage of the term collaboration can lead to a degree of confusion. In summary, therefore, collaborations are structural elements that simply identify elements that will interact in some way - they identify 'what'. The definition of 'how' these collaborations behave is stated using...
