UML Uses case Actor choice

Question

I'm working on a dashboard project. I'm using UML for modeling. The first task is use case diagram.

The clasic actor only has one action that is requesting the data he wants. But all the work is done by the application. How to model this in UML use case ?

Answer 1

• An actor can have one or many use cases connected to him. Their number is not limited.
• Yes, every use case=behaviour is realized by the application, or as UML standard names it, by the subject (of your project).
• In Use Case diagram the subject is defined by its behaviours. The simplest form of Use Case diagram has NO actors, only ovals of use cases and nothing else. You should name all behaviours/actions of your system. It is a list, only in a graphic form. All further steps are not necessary.
• You could also define different kinds of users for your system and say, what users can use what actions. For starter it is better to stop HERE. Or, at least, to create more thorough use case diagrams as other ones.
• Some actions could be connected by including or extending dependencies.
• The next step could be joining some use cases in groups and name them as subsystems. Do not mix them with real SW or HW components! They could become such, but you'll decide it later.
• The next step could be including elements of other diagrams or the whole other diagrams in the use case diagram. State machines are the first candidates.