1. Other UML Diagramming Techniques
CS 124

2. UML Diagramming Techniques
Class Diagrams
Use Case Diagrams
Interaction Diagrams
Sequence diagrams
Collaboration diagrams
State Diagrams
Others (e.g., Activity Diagrams, Package Diagrams)

3. State Diagrams Depicts object behavior across use cases
State: collection of values of attributes
State-behavior relationship
state is updated by some behavior carried out
Notation
States: rounded rectangles
Arrows: state transitions
Labels on Arrows: event/action/use case

4. Example 1: Book in a Library System
start
Reserved
release
New
reserve
Borrowed
borrow
activate
return
Available

5. Example 2: Claim in an Insurance System
start
Rejected
Closed
Pending
Customer disputes
evaluation
Officer confirms that premium payments made and claim is legitimate
Approved

6. When to Draw State Diagrams
State diagrams are good at describing the behavior of an object across several use cases
Use state diagrams only for those classes that exhibit interesting behavior, often the main classes of the system

7. State Diagrams Help Complete System Design
State diagrams often reveal use cases overlooked in earlier analyses of the system
State diagrams provide hints on which attributes are necessary for a given class

8. Activity Diagram Represents sequence of activities
Depicts condition, iteration, and parallel activities
When to use:
Analyzing use cases
Alternate way of describing a use case
Depicting use case sequences/workflow
Describing method behavior

9. Activity Diagram Notation
Oval - activity
Start and end buttons
Links between ovals to depict sequence
Diamond – conditional branch and merge
Bar – fork and join (concurrent activities)

10. About Activity Diagrams
Helps in understanding system behavior, but … it does not provide an object-oriented perspective!
Suggestion: just use as a tool to clarify complex sequential/parallel relationships between behavioral components

11. CRC Cards Not really part of the UML
But helps in construction of Class Diagrams and Interaction Diagrams
CRC: Class-Responsibility-Collaboration
Role-playing:
Team members represent classes
Each member/class holds an index card

12. CRC Cards, continued
Team goes through each use case and role-play object interaction
Responsibilities (which end up being methods) are noted on the index card
Use of an index card is deliberate
Responsibilities ought to be evenly distributed across the classes that interact
Overloaded classes become immediately apparent

13. CRC Cards and UML Diagrams
Role-playing activity for each use case maps directly to interaction diagram construction
Each card provide class details (methods) for the class diagram

14. Package Diagrams Systems are often large Package diagrams depict
Can be divided into subsystems
In object-oriented contexts, subsystems are packages; packages are groups of classes
Package diagrams depict
grouping
dependencies between packages

15. Package Diagram Notation
Folder: Package
Dotted arrow between folders: dependency link
Two variations
Abbreviated: name in folder
Detailed: name on folder tab, rectangles representing classes in folder area

16. Summary
Use the UML as a communication tool across the different stages of software engineering
Diagramming techniques are primarily a design tool but helpful in analysis as well
Important to note what stage or perspective (conceptual, specification, implementation) you are in
There are correspondences between diagrams with actual code