UML Activity diagram
A graphical representation of data flow
Data flow diagram in OO context
Userful to specify software or hardware system behaviour
Model Business Activity
Model System functions
Used during Requirements elaboration
Use during Low Level Design - to provide functionality elaboration
Components
Activity - a unit of executable functionality
A rectangle with rounded edges
Name written inside
Transition from one activity to the next using a line with an arrow
The execution of a activity represents some transformations or processes in the modelled system
Initial node - A black dot. Represents the flow start
Diamond - decisions
Branches represent alternative paths taken based on a boolean expression
Guards are specified on the outgoing edges
Can also merge node - bring together multiple alternative flows
Synchronisation bar - forks or joins parallel flows of control
Forking or joining of parallel flows of control
Can Join
Or fork
Final Node - black dot with a circle around it. End of all processes or workflows
Flow Final cicle with an X - end of a process in a single flow
Swimlanes - partition activities into groups. Each group represents the business organistation responsible for those activities
Has a unqiue name
Can represent a real world entity
Activity belongs to a single swim lane
Time event - hour class, with the time constraint. Flow continues when the time expression is statisfied. I.e. every day at 2am.
Send and recieve signsals
