UML / Sequence Diagram

[Lukas Moser]

I wonder what the left most 'item/symbol/object' has to be to start the diagram with.

In 'Sun Certified Enterprise Architect for J2EE Technology' by Mark Cade the sequence diagrams start with an actor. However I belive that this does not conform to UML 2.0.

StarUML - that I use to draw the diagrams - does not support to have an actor and it is not possible to draw the first arrow without starting from an object.

What is the correct way to draw the first arrow?

Thank you very much for your help!

[Gabriel Claramunt]

I'm using StarUML (v5.0.2) too, and I have actors that start the flow sending messages...
I have my actors defined in the use case model, and the sequence diagrams in the desing model, and works fine.
Did you try drag & drop the actor in the sequence diagram?
BTW, just curious, why do you believe that starting a sequence diagram with an actor doesn't conform to UML 2?
[ June 25, 2007: Message edited by: Gabriel Claramunt ]

[Lukas Moser]

It works as you say. And I think now, that actors are allowed in sequence diagrams.

Thank you!!!

[Gabriel Claramunt]

Sometimes it can be confusing. In a sequence diagram, you don't have classes ( or actors), instead you have instances of them...

[Leo Gao]

I can not find actor icon under the sequence diagram menu, how can you get the actor icon in sequence diagram?

[Leo Gao]

I answered my question and find it finally.