Table 4: Mapping between quality scenatios [17] and use cases - case (b).
Quality scenario part Use case part Comments
Environment (context) An exception point in the extended use case
Stimulus Source Internal (the system itself) or external (a primary actor)
Stimulus The event that satisfies the condition in the exception point
Response The MSS of the extending use case and any sub-scenarios branching from it
Response measurement Post-conditions If the extending use case returns to the extended use case upon completion, then the results are implied by the post-conditions of the extending use case. Other wise – by the post-conditions of the extending use case