Hi Preet,

Yes, you can create the Use cases. Here, the Actors will be users that are receiving the notifications and accordingly completes the actions (like scheduling freight, editing report etc)

So, Actor can be: Shipping manager, Freight Scheduler, Report personnel, etc (This you can get from your current requirement)

ABC System can't be an actor, as in the USe case diagram, actors are all external entities who are directly working with the system.

Regarding your query; you can put the functions as use case in the diagram and text: like User can change words, user can generate reports, etc

You have to also, think on the alternate paths, business rules etc. So, your use case may contain the activity diagram, business rules and any prototype if you wish to create, can be incorporated.

As suggested by some user, always go by top to bottom approach. This will make your analysis robust.

Regards,
Dipal