Phase 1 - Use cases
The goal in this phase is to specify scope for system to be
developed and describe its use cases. Concentrate on the quality of
the textual descriptions of the use cases - they lay the foundation
to all later development phases.
Tasks
- Update the subject description for possible missing features (use general knowledge and imagination).
- Depending on the assignment topic: think about the business
processes that the system to be developed supports. Draw an
activity diagram (or
multiple diagrams if necessary) about the most important process.
Use "swimlanes" and mark each step with actor (role, organization
or system) that works the activity. Most use cases related to the
system should appear in the activity diagram as single
steps.
- Design a use case diagram, containing use cases, actors, their relations to the use cases and possible relations between use cases (generalization, include, extend)
- Specify textual descriptions
of the most essential use cases (choose 2-4 use cases,
depending on project group size).
Tips
- Use cases should be modeled similarly to the the example
assigment
- Use case descriptions should always contain use case name, steps, and exceptions (=alternate routes). The steps describing activities should be short, clear, and phrases should use the word order subject-predicate-object (the subject can be an actor or the system). You can use the following use case template: (html, doc, odt).
- About the writing conventions see Cockburn's style guidelines
- Remember:
Use cases are not functions
- As an example of a longer use case see
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