Operations (Use Cases)
Describe the functionality in terms of use cases.
What are the operations system will provide to them?
Associate with the explicit requirements they fulfil
Provide illustrations. (Use case diagrams)
Rank in order of importance.
Use Case names are typically terse (short) verb phrases. It seems to work well
to attempt that your Use Case names express the goal of the user's interaction with
the system.
E.g.
'Print Report' rather than 'Report'
'Calibrate System' rather than 'Settings'
Etc.