Defining use cases

System engineering use cases show specific operations of the system and how actors view the intended behavior of the system. Use cases are linked to requirements to ensure that all requirements are satisfied by at least one use case. If necessary, a requirement can be linked to several use cases. Operational modes of the system help to organize and rank use cases according to hierarchy. For example, an airplane might have several operational modes - take off, fly at a wanted altitude, and land. You can define a higher-level use case, which covers operational modes and then derive separate use cases for each operational mode.

Roles:

• Systems engineers

Artifacts:

• Use case diagrams