Introduction to UML Part 2 Behavioral Modeling

Sequence (event) diagram Describes object interaction Typically captures behavior of a single use case Notation: message return

Sequence (event) diagram lifeline object message

State diagram Describes all possible states of an object and activities associated with the state How the state changes as a result of events that reach the object States include start and end States can be packaged into superstate

State diagram Superstate transition activity state Start state

Activity Diagram Useful for describing behaviors with a lot of parallel processes Parts: start/end state activities synchronization bars guards

Activity Diagram activity Descision activity Synchronization bar guard

UML is effective for modeling large, complex software systems It is simple to learn for most developers, but provides advanced features for expert analysts, designers and architects It can specify systems in an implementation-independent manner 10-20% of the constructs are used 80-90% of the time Structural modeling specifies a skeleton that can be refined and extended with additional structure and behavior Use case modeling specifies the functional requirements of system in an object-oriented manner Behavioral modeling captures interactions between objects, state transitions within objects, depicts flow of control. Ideas to Take Away