Use Case Modeling

Hi,I’m a new UML user,
i want to ask,when make a use case diagram,do we make it separately for each actor?,
tenkyu,

Hi user,

Thanks for your post. Use Case Diagram is presenting the functionality of a system and the goals and actors involved in the system. And UML is a general modeling language, it does not have a fixed rule of how to use it. Therefore the actor(s) or goal(s) being covered in the use case diagram depends on the scope you focus on.

Sometimes you need to model a large system which involves lot of actors and goals, then you may need to divide it into several diagrams so that you need not to squeeze everything on a single diagram. If it’s done on paper it will be difficult to define reference between models/diagrams, which is achieved easily by a modeling tool.
In our tool, you can define shape, diagram (or even URL, document, folder) as reference of a model, you can also add sub-diagram on a shape for drilling down the details.

You can find details of adding reference and sub-diagrams from the following links respectively:
http://content.europe.visual-paradigm.com/media/documents/vpuml61ug1/html/Chapter_4_Visual_Modeling/Chapter_4_Visual_Modeling.html#toc-0-3
http://content.europe.visual-paradigm.com/media/documents/vpuml61ug1/html/Chapter_4_Visual_Modeling/Chapter_4_Visual_Modeling.html#toc-0-2

Hope these help. If there is any further inquiry, please do not hesitate to ask.

Best regards,
Lilian Wong