A Student Guide to Object-Oriented Development

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A Student Guide to Object-Oriented Development

• Chapter 8 Activity diagrams

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Activity diagrams

• show the internal flow of control in a process
• can be used to model processing at different
  levels e.g.
• high-level workflows in an organization
• detail of what happens in a use case
• detail of how an operation works

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Activity diagrams

• can be used to represent
• sequence
• selection
• iteration
• can also illustrate where different activities
  can be carried out in parallel

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Modelling a sequence of activities
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Notation
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Modelling alternative courses of action (1)
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Activity Diagram (UML)
Decision point
Synchronization bar End Task
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Activity Diagrams

• Activity diagrams extend statechart diagrams
  and present a sequence of "activities" and how
  the execution path progresses from one activity
  to another.

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Activity Diagrams

• Activity diagrams can also present

• decision points conditions that change the flow
  of actions
• parallel execution paths
• objects affected by actions

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Example Activity Diagram
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Modelling alternative courses of action(2)
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Modelling iteration of activities
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Modelling activities that are carried out in
parallel(1)
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Modelling activities that are carried out in
parallel(2)
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Alternative and parallel activities
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Swimlanes
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In alternative activities the diamond symbol may
be omitted
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Including objects and object flows