Roman,
You sure can! Have a look at this lesson link for UML 2.0 http://www.agilemodeling.com/artifacts/packageDiagram.htm about half way down as long as you add value to the reader "how you categorize the diagram is of little real consequence." As you can see there is an association between packages.
UC packages are not like CLASS packages. They need not follow the same rules. Read the rest of the link for some tips and tricks.
Read on here, if you are interested in Uce Case desgin a more a advanced level ....
When formulizing a Use Case in an advanced design house...Formulizing a use case is about taking the diagrams and narratives and turning them into a real object oriented system
- "A formulized use case goes through three phases: realization, refinement, and reification
- use case realizations are the design models (activity diagrams, state machines …) that are translated from use case scenarios
- use case refinement is about gathering all of the use cases for each modeling element contained within the system and model the collaborations among these elements (subsystems and classes)
- use case reification is a method for turning use cases and actors into classes of the system
- reification is literally the process whereby concepts become material
- also called hypostatization its about treating an abstract concept as if it were a real concrete thing (use cases as eventual instantiated objects)
- the use case therefore becomes part of a class category
- each use case is an operation of the system
- ‘AllActors’ becomes another class
- each actor is an instance of ‘AllActors’
- a class is then created for each use case
- each scenario is added as an operation of its class
- an actor object starts a scenario by sending a use case message to the system, which in turn instantiates a use case object from its class
- the second message sent by the actor is the scenario name, It is sent to the instantiated use case object (this tells the use case object which
- scenario it will be doing)
- additional objects can then be instantiated by the scenario that are an actual part of the system
the actor interacts with these new class objects normally, but can also send additional use cases messages (to System) or scenario messages (to use case objects)"
just in case you were wondering.
Perry McLeod, CBAP, PMP