Tool Mentor: Designing Subsystems
Using Rational XDE Developer - .NET Edition
Purpose
This section provides links to additional information related to this tool mentor.
The steps in this tool mentor match those in the activity. Links to topics
in the Rational XDE™ online Help are marked with 
.
Overview
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.
- Create class diagrams as needed. See .
- Add subsystems and classes. See Tool Mentor: Identifying Design Elements Using Rational XDE for guidance on adding new subsystems and classes.
- 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 .
- Drag and drop classes and interfaces onto the diagram to create objects for interaction. See .
- Add messages or stimuli between objects. See .
- Assign operations to messages. See .
For more information, refer to the following topics in the Rational XDE online Help:
Document Subsystem
Elements
Refer to in the Rational XDE 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 in the Rational XDE online Help.
