How to model a context diagram with EA?

[Eiberle]

Hi all,

Several books about system architecture recommends the usage of a context diagram showing the relations of  system under development (SuD) and the environment like other systems or actors.
This looks for me a reasonable approach so I want to built up this model using EA and standard UML constructs.
To model the diagram, some books recommend to use a use case diagram, other mention to use some kind of package diagram, while other are using a simple class diagram.

So I am a bit confused about all of this. Maybe someone else run into the same problems? For me using a component diagram for this would be a reasonable approach. Will this be the right way? How can than the SuD be represented? As far as I know there is only a <<subsystem>> stereotype, but no <<system>>stereotype.

Maybe there is already a generally accepted solution about this. If yes, please let me know about it. Also if you have created a context model using EA, please let me know about it.

Thanks in advance for your comments about this topic.

[qwerty]

Clearly it depends upon what you want to design. If you want to show behavior you'll need to start with UC diagrams. Is it structure then Component diagrams are the way to go. In most cases you want to model a mix of it all and there you need both. If you suffice with just a single diagram at all you'd likely be able to save modeling at all  

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[babdev]

In the past I have used a use case diagram to create a context diagram, using actors for external systems and people and a class with the <<system>> stereo type to represent the system under development. You're right that there isn't a system stereotype in the list provided but I just type it in. Not sure whether this is the correct use of UML notation but it gets the message across.

[Eiberle]

For my understanding the context diagram is more about structure than about behavior. For this I have to move in the direction of a component diagram.
I will model the SuD as a component using my own <<system>> stereotype. For people using the system I will use the actors and for other systems I will also use some components.

I have just tried the Use Case way which will work, but I wanted also to add some interface and communication media information into the context diagram. I guess this information can not be added to a use case diagram with actors only?

[qwerty]

You can put any element in any diagram. The diagram types in EA just offer a default set of the most used elements but you can take other elements from any toolbox.

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