CS 691z791z Topics in Software Engineering

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CS 691z/791zTopics in Software Engineering

• Chapter 13 Activity Diagrams
• Chapter 19 Basic Statecharts
• Arlow and Neustadt, 2002
• March 8, 2007

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Outline

• Activity diagrams
• Actions and subactivity states
• Transitions
• Decisions, forks, and joins
• Swimlanes and object flows
• Signals
• Basic statecharts
• Syntax
• States
• Transitions
• Events

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Activity Diagrams Actions Subactivities.

• Actitivity diagrams
• A form of OO flowcharts, a particular case of
  statecharts
• Attached to modeling elements to describe
  behavior
• Typically related to use cases, classes,
  components, collaborations, operations methods
• Contain actions (atomic, uninterruptible,
  instantaneous) and sub-activities (non-atomic,
  interruptible, may take time)
• Examples of actions, Fig. 13.2 Arlow Neustadt

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Activity Diagrams .Actions Subactivities

• Actions Start and stop states, Fig. 13.3 Arlow
  Neustadt, 2002
• Subactivities Examples, Fig. 13.4 Arlow
  Neustadt, 2002

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Activity Diagrams Transitions

• Transitions in activity
• diagrams, Fig. 13.5
• Arlow Neustadt, 2002
• Transitions in activity
• diagrams occur when the
• states finish their work

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Activity Diagrams Decisions

• Decisions in activity
• diagrams, Fig. 13.6
• Arlow Neustadt, 2002

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Activity Diagrams Forks and Joins

• Fig. 13.7 Arlow
• Neustadt, 2002
• Activity diagrams
• allow modeling
• concurrent workflows

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Activity Diagrams Swimlanes

• Fig. 13.8 Arlow
• Neustadt, 2002
• Swimlanes are
• typically used
• for use cases,
• business modeling,
• and workflow
• modeling

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Activity Diagrams Object Flows

• Fig. 13.9 Arlow
• Neustadt, 2002
• Activities may input
• and output objects
• and may modify
• object states

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Activity Diagrams Signals

• Fig. 13.10 Arlow
• Neustadt, 2002
• A signal is a
• package of
• information
• transferred
• asynchronously
• between objects

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Statecharts

• There are two main modeling elements in
  statecharts states and transitions.
• Example of a simple state machine, Fig. 19.2
  Arlow Neustadt

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Statecharts Syntax

• Summary of UML state syntax, Fig.19.3 Arlow
  Neustadt, 2002

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Statecharts Transitions

• Summary of UML transition syntax, Fig.19.4 Arlow
  Neustadt, 2002
• Where
• Event internal or external occurrence that
  triggers the transition
• Guard condition boolean expression, when true
  transition allowed
• Action some operation that takes place when the
  transition fires

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Statecharts Events.

• Events can be of four types
• Call event
• Signal event
• Change event
• Time event

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Statecharts .Events

• Example of a call event, Fig.19.6 Arlow
  Neustadt, 2002

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Statecharts ..Events..

• Example of signal event
• Fig.19.7 Arlow Neustadt,
• 2002
• Modeling the receipt a signal
• Fig.19.8 Arlow Neustadt,
• 2002

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Statecharts Events.

• Example of a change event, Fig.19.9 Arlow
  Neustadt, 2002

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Statecharts .Events

• Example of a time event, Fig.19.10 Arlow
  Neustadt, 2002

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Statecharts What next?

• An advanced statechart Ch. 20, Fig. 20.4, Arlow
  Neustadt, 2002

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Extra Analysis classes vs. Design classes
Fig.15.2 Arlow Neustadt, 2002