8.2. Derived Attributes
Because an Executable UML model captures the information inherent in a domain, redundant attributes are generally frowned upon. However, there are occasions when a clear understanding of a domain is best served by capturing the dependency between attributes explicitly.
Definition: A derived attribute is an attribute whose value can be computed from other attributes already in the model.
Figure 8.9 shows two derived attributes, each prefixed by a / (slash).
Figure 8.9. Derived Attributes
The attribute ProductSelection.selectionValue can be defined in OCL like this:
context Selection inv: Self.selectionValue = ...
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