Testing the Robustness Extensions

To test the extensions we have created, we will create a small robustness diagram to analyze our use case.

1. Right-click your model node in the Browser, and select New > Communication Diagram.
   In addition to the standard Toolbox, a custom toolbox is provided with tools you have defined to create boundary, control, and entity objects.
2. Drag the Customer actor from the Actors category in the Browser into the diagram to create a shortcut. Then create one each of the boundary, control and entity objects, and name them Internet Browser, Application Server, and Database Server respectively.
3. Use the Instance Link tool in the standard Toolbox to connect the Customer to the Internet Browser to the Application Server, to the Database Server.
4. Create the following messages on the Messages tabs of the instance links property sheets:

   Direction	Message name	Sequence number
   Customer - Internet Browser	Stock value query	1
   Internet Browser - Application Server	Ask value to app server	2
   Application Server - Database Server	Ask value to db	3
   Database Server - Application Server	Return value from db	4
   Application Server - Internet Browser	Return value from app server	5
   Internet Browser - Customer	Return value	6

   
   
   
5. Select Tools > Check Model to display the Check Model Parameters dialog box, in which the custom checks we have created appear in the Instance Link category:
   
   
   

   Click OK to test the validity of the instance links we have created.

6. Right-click the model node in the Browser and select Properties to open the model property sheet. Click the Preview tab to review messages sent for our use case: