I'm trying to build a Use Case diagram for Automated Examing System, one of the requirements is: The system can start a timer for the exam, and stops it at a certain time, with that, the examinees won't be able to continue.
is there a way to do that ?
You could introduce an actor called “Time” to initiate scheduled events. That is one of options, it does not have to be an actor.
Have a look at this, maybe it will give u some ideas.