Sparx Systems Forum

Discussion => Uml Process => Topic started by: Stephen Kropp on September 24, 2016, 07:21:29 am

Title: Actors in a BDD
Post by: Stephen Kropp on September 24, 2016, 07:21:29 am
Can anyone help me understand the finer details of a BDD, I'm trying to understand if I can add an Actor to a BDD instead of creating a block for the same actor? EA appears to let me add Actors to a BDD but is there a reason why I shouldn't do this?

I have been using "A Practical Guide to SysML" by Friedenthal et al. for reference but all of the examples from that book are using blocks.

Thanks,

Steve
Title: Re: Actors in a BDD
Post by: PeterHeintz on September 26, 2016, 06:30:11 pm
Yes SysML allows you to put Actors on a BDD.

What to use when, depends on what you want to achieve or is even sometimes a matter of taste.

If I want to show that e.g. a person is acting from outside with a system I typically use an actor. If e.g. the person is part of the system, I typical use a block to represent the person.
Title: Re: Actors in a BDD
Post by: Stephen Kropp on September 27, 2016, 12:29:31 am
I try to not have duplicate items within the model representing the same thing so it bothers me that I have to make a separate swimlane for my actors and that it appeared that I needed to make, yet another block for the actors too.

Thank you!
Title: Re: Actors in a BDD
Post by: PeterHeintz on September 27, 2016, 12:59:33 am
Why do you need to make separate swim lanes?

As I have said, you do not need to duplicate actors.

As long as the language capability of an UML/SysML actor is sufficient for you, use the UML/SysML actor.
If you need more language capabilities to describe the “concrete actor”  you can use e.g. a Block or a Class to do that, instead of using an UML/SysML actor.
If you want to have it duplicate for some reasons you can do that as well, but in this case I would put those in a relation to state the both are the same.
Title: Re: Actors in a BDD
Post by: Stephen Kropp on September 27, 2016, 01:34:11 am
Thanks for the clarification. I didn't fully explain my response before. I was simply using examples of things that I (think I need to) duplicate using SysML and was including a block representing an actor as one of those items. I am glad to see that I don't need to do this.

So in your example, since you use blocks if the actor is part of the system, you relate a use case to a block in the same way you would relate a use case to an actor?

Is there a better way to relate an actor to a swim lane other than just putting the actor in the swim lane?

Thanks for your help!
Title: Re: Actors in a BDD
Post by: qwerty on September 27, 2016, 01:40:33 am
Usually a swim lane is just a graphical element on a diagram and you should not use them since they do not really add semantics to the model. Instead use pools/lanes and classify them with your actor. They are real elements and you can put other elements inside which participate in activities.

q.
Title: Re: Actors in a BDD
Post by: PeterHeintz on September 27, 2016, 01:54:17 am
Regarding your use case to block connection question, yes I relate a block in the same way as an actor.
For swim lane stuff see response from qwerty.