Hello I got the definition below for an actor. That means the system cannot be an actor to itself. I was wondering what if the system is supposed to display certain elements on a screeen. In that case would the system be its own actor in the system? Probably not . Then how would I present that in a use case diagram ?
Actors: An actor is a person, organization, or external system that
plays a role in one or more interactions with your system. Actors are
drawn as stick figures. – See more at:
http://www.agilemodeling.com/artifacts/useCaseDiagram.htm#sthash.1jE5S2CY.dpuf”
The system can display certain elements on a screen, means that an actor can “Check those elements on the screen”. Try not to describe your system from the point of view of the “system”, but from the “Users” point of view: what can they do with the system?
I believe an example would help:
Let’s say I want to talk about an ATM as a system. The use cases the “Bank Customer” can use:
- Withdraw Money
- Check Account Balance
It would not be ok to describe from the Banks point of view. But If you try you should get something like: The system can:
- Give money on request (maps to withdraw money)
- Display balance (maps to Check acct. balance)
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Who are the viewers of the screen? Aren’t they the ones who “want” to view the information?
About the question “Can a system be its own actor?”
Perhaps a system can be its own actor. If you view a system as an intelligent goal driven agent that is proactive towards its own goals and acting based on its beliefs, desires, obligations, and intentions (see, amongst others the work of the Intelligent Systems group at the Utrecht University), then one could vie that system as its on actor.
But let me emphasize, I don’t think this way of modelling would help you for the display system.
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