Overview 

This tool mentor supports Designing Subsystems with Rational XDE Developer - Java Platform Edition.

• The steps in this tool mentor match those in the corresponding task.
• Links to topics in XDE online Help are marked with .
• The following steps are performed in this tool mentor:
• • Distribute Subsystem Behavior to Subsystem Elements
  • Document Subsystem Elements
  • Describe Subsystem Dependencies

Distribute Subsystem Behavior to Subsystem Elements

Classes and other subsystems are added within the subsystem to realize the subsystem interfaces.

The collaborations of model elements within the subsystem must be documented using sequence diagrams that show how the subsystem behavior is realized. Each operation on an interface that is realized by the subsystem must have one or more documented sequence diagrams. This diagram, which is owned by the subsystem, is used to design the internal behavior of the subsystem.

1. Create class diagrams as needed. See Adding Diagrams .
2. Add subsystems and classes. See Tool Mentor: Identifying Design Elements Using Rational XDE for guidance on adding new subsystems and classes.
3. Document how each interface operation is realized, as follows:
   • Add a collaboration instance for each interface operation. Name it after the operation. (In the Model Explorer, right-click the subsystem package, and then click Add UML > Collaboration Instance.)
   • Create an interaction instance with the same name. (In the Model Explorer, right-click the collaboration instance, and then click Add UML > Collaboration Instance.)
   • Create a sequence diagram for this interaction instance. See Adding Diagrams .
   • Drag and drop classes and interfaces onto the diagram to create objects for interaction. See Adding Shapes to Diagrams .
   • Add messages or stimuli between objects. See Adding Messages or Stimuli .
   • Assign operations to messages. See Assigning Operations to Messages or Stimuli .

For more information, refer to the following topics in the Rational XDE online Help:

• Working with Class Diagrams
• Working with Interaction (Sequence) Diagrams
• Modeling Java and Web Applications

Document Subsystem Elements

Reference: Documenting Model Elements

Describe Subsystem Dependencies

When an element contained in a subsystem uses some behavior of an element contained in another subsystem, a dependency is created between the enclosing subsystems. To improve reuse and reduce maintenance dependencies, express this situation in terms of a dependency on a particular interface of the subsystem, not upon the subsystem itself nor upon the element contained in the subsystem.

Reference: Adding Dependency Relationships