UML replacement for context diagram

Question

According to the UML context diagram, the context diagram does not exist.
So my question is: which of the UML diagrams is good to show something like this and how to do it?

Answer 1

I just found the following definition: http://en.wikipedia.org/wiki/System_context_diagram This is probably what you need. :)

A context diagram defines the boundary between a system or part of a system and its environment, showing the objects that interact with it.

There is no single diagram in UML that would display this definition, but I have some good news - there are several diagrams (out of 14) that can show the boundary between the system and its surrounding world from different points of view.This is much more flexible than contextual diagram.

First of all, I would mention a special UML element - the border . It can be used in any type of chart to show some kind of distinction. You might want to use it to visually distinguish between a system and its environment, especially in situations where this is not explicit.

The following diagrams may display the boundary between the system and its environment:

• The use case diagram (your example) maintains context explicitly at the functional level. Use cases are elements of a developed system, while actors are external objects (systems or people). Before the mentioned boundary is often used to visually distinguish between a system and its environment.
• The component diagram is used to model some software modules (applications, databases, external systems, libraries, etc.). You can see it both internal and external components and a way of interaction. The border can be used to clearly identify the dividing line.
• An action diagram can show the processes of your system / business / usage. SOme activities can be performed internally, others from the outside. Here you do not need a border, but the so-called swimlanes to depict who does what.
• Sequence / collaboration diagrams are another option. They show message sequences between several objects. If you separate these objects internally and externally and terminate them with borders, there is another context diagram. :)

UML is flexible, there are probably additional options, but I think that’s enough to get this idea.

Answer 2

The names of your association are services. UseCase in the center of the diagram is the context for defining services. See Usecase Chart:

Answer 3

This can be done if used.

http://en.wikipedia.org/wiki/Use_case

EDIT:

After reviewing it, the case usage diagram should be the next step after the operations are defined, so first you make a system sequence diagram.

http://en.wikipedia.org/wiki/System_sequence_diagram

Answer 4

I use collaboration diagrams for this. Therefore, for each major scenario of each use case, draw a collaboration diagram showing the participants, with the application as a single whole in the middle, and the messages moving around show how the application interacts with the participants to execute the script.

(I don’t enter too many details in the messages - I just want to show that there is delegation of responsibility and some kind of interaction, but I don’t need the details of the actual messages, views, data, etc.)

Answer 5

I see that the context diagram has a special appeal. It combines well with business users, which very simply shows them the scope and sides of the system. Thus, I tend to create a context diagram, even in the context where UML is common.

Answer 6

If you are happy with the transition to an incomplete subset of UML, which is SysML , you may have appropriate context diagrams.

However, context diagrams in SysML are just block diagrams showing the system context ... and the block diagrams are the same as the UML2 class diagram, where the classes have the SysML: Block stereotype.

So, you can define your context diagram in terms of aggregation of blocks in your system with the corresponding stereotypes, based on the class diagrams of UML2.