Week 14: Activity Diagram

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Week 14 Activity Diagram Interaction Diagrams
IFS 410 Advanced Analysis and Design
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UML Techniques for OO Design

• Activity Diagram
• Communication (Collaboration) Diagram
• Sequence Diagram
• Package, Component, Deployment Diagrams

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Activity Diagrams

• Shows the conditional logic for the sequence of
  system activities needed to accomplish a business
  process
• Clearly shows parallel and alternative behaviors
• Can be used to show the logic of a use case

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Activity Diagram

• Focus on system behavior
• Model an objects workflow during program
  execution
• Model the actions the object will perform and in
  what order
• UML representation
• Action state ( rectangle with its left and right
  sides replaced by arcs curving outwards)
• Action order ( arrow with a stick arrowhead)
• Initial state (solid circle)
• Final state (solid circle enclosed in an open
  circle)

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Components of Activity Diagram
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Fig. 5.30 Activity diagram for a BalanceInquiry
object.
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Fig. 5.31 Activity diagram for a withdrawal
transaction.
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When to Use Activity Diagrams

• Activity diagrams are useful when you want to
  describe a behavior which is parallel, or when
  you want to show how behaviors in several
  use-cases interact.
• Use Communication diagrams when you want to show
  how objects collaborate to implement an activity
  diagram. Use a state (chart) diagram to show how
  one object (attribute) changes during its
  lifetime.

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Interaction Diagrams

• Model interactions use UML
• Communication diagrams
• Also called collaboration diagrams
• Emphasize which objects participate in
  collaborations
• Sequence diagrams
• Emphasize when messages are sent between objects

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A communication diagram
Fig. 7.26 Communication diagram of the ATM
executing a balance inquiry.
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Sequence diagrams

• Help model the timing of collaborations
• Lifeline
• Dotted line extending down from an objects
  rectangle
• Represents the progression of time
• Activation
• Thin vertical rectangle
• Indicates that an object is executing

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A Sequence Diagram
Fig. 7.28 Sequence diagram that models a
Withdrawal executing.
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Elements in Sequence Diagrams
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Creating a Sequence Diagram