Look at the
object fl ow in the activity diagrams of our use cases (see Section 2.4.6). The data
we have denoted as incoming or outgoing data near the actions represent the
domain information our system is dealing with.
We use the stereotype ?«domain?» to denote domain blocks. Blocks do not normally
have operations, and they have only few attributes. The types of attributes
are generally not stated, because they are part of design or implementation details,
which are not of interest in the domain knowledge model. Here it is irrelevant
whether it ??™ s a string or char[] , an int or integer .
In our object fl ow model we have made assumptions about the structures of the
objects. For example, the object fl ow in the use case start car usage implies that
the object customer includes the PIN check code, or that the object usage right
includes information about emergency driving , and so on. We can also derive relationships
between objects.
These structures have to refl ect in the domain knowledge model. We use the
model element association to model structural relationships between blocks.
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