The important thing is to fi nd out whether
the information starts the dialog, or whether the information is transmitted in the
course of a dialog. If the user started the dialog, we have found a new use case.
Otherwise, we track back the dialog to fi nd the trigger.
The use case name is formulated from the user ??™ s view. Imagine you are supposed
to mark a button at your system that triggers the use case for users to
understand what the button does.
Though the naming is often independent of a direction, verbs like buy , sell ,
or enter , actually imply a direction. It is important to understand whether the
actor or the system buys or enters something. From the triggering actor ??™ s view a
2.4 Modeling Use Cases
Table 2.9 Summary: Identifying use cases.
Reference card: Identify use cases.
Incoming and outgoing data
Requirements:
General requirements to the system.
System context:
System with actors.
Use cases:
Services provided by the system.
Motivation/description
Why? Use cases describe the system ??™ s services that are perceived and requested
from the outside, which means that they are an important view on the requirements.
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