Concept: Include Relationship |
"Include" use cases factor common or special behavior out of concrete use cases.
Relationships
Related Elements | Structure the Use-Case Model
Main Description
If a use case contains a segment of behavior of which only the result, not the method for getting the result, is of any importance to the rest of the use case, this behavior can be factored out to a new inclusion use case. The original use case then becomes the base use case in an include-relationship with the inclusion use case. An include-relationship between two use cases means that a use-case instance following the description of the base use case also needs to follow the description of the inclusion use case in order to be complete. The include-relationship can help clarify a use case by: Isolating and encapsulating complex details so they do not obscure the real meaning of the use case. Improving consistency by including behavior which are included in several base use cases. Generally, more than one use case must include an inclusion use case to make it worth it to maintain an extra use case and the include-relationship. Only the base use case knows of the relationship between the two use cases; no inclusion use case knows what other use cases includes it. Describe the include-relationship by briefly stating the purpose of the inclusion, as well as the location in the base use case at which the inclusion is to be inserted. When describing the flow of events of the base use case, you must refer to the inclusion at the location in which the inclusion is inserted. For more information, see Guideline: Defining Include Relationships.
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