Tool Mentor: Designing Subsystems Using Rational Software Architect for WebSphere
This tool mentor describes how to design subsystems using the RSA-W modeling environment.
Tool: Rational Software Architect for WebSphere
Extends: Designing Subsystems Using Rational Software Development Platform
Main Description


The following steps are performed in this tool mentor:

Additional Tool Information

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 help book iconCreating and Modifying Class Diagrams .
  2. Add subsystems and classes. See Identify Design Elements 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 and then click Add UML > Collaboration.  
    • Create an interaction with the same name. In the Model Explorer, right-click the collaboration and then click Add Diagram > Sequence Diagram. See help book iconSequence Diagrams .
    • Drag and drop classes and interfaces onto the diagram to create objects for interaction.
    • Add messages or stimuli between objects. See help book iconSequence Diagrams
    • Assign operations to messages. See help book iconSequence Diagrams.  

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

  • help book iconModeling Static Structure by Using Class Diagrams
  • help book iconSequence Diagrams

Document Subsystem Elements

Refer to help book iconDocumenting Model Elements in the online Help.

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.

Refer to help book iconDependency Relationships in the online Help.

Additional Tool Information

help book iconManaging UML Diagrams