Object Oriented Analysis

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Object Oriented Analysis

• Unified Modeling Language
• By Mary Biddle

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Use Cases

• Use Case a behaviorally related sequence of
  transactions that make up one standard use of the
  system being modeled.
• Use Cases are generated from requirements
  specifications and from interviews with
  users/clients.
• Why Use Cases?
• Customers can describe what they want the system
  to do better than the entities within the system.

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Actors

• User cases are stimulated by actors.
• Actors are users outside the current system
• Actors may be users that play a particular role
• Actors may be other systems or devices that
  either stimulate the system or receive output
  from the system
• Use Cases describe the users view of the system.

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SafeHome Use Case
Homeowner
Motion Detector
Police
Siren
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Create Packages (Subsystems)
Sensors
Motion Detector
Alarm
Security Control
Police
Homeowner
Siren
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Packages
Door Open Detector
Sensors
Window Open Detector
Motion Detector
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Packages
Sensors
Motion Detector
Security Control
Alarm
Police
Siren
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SafeHome State
Activate Security
Security Off
SecurityOn
Deactivate Security
Intruder Detected
Alarm
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Encapsulation

• Encapsulation creating a high level of
  abstraction while hiding the detailed
  implementation
• Information Hiding hide the implementation so
  when requirements change the impact to the design
  is minimized.
• Using these concepts when creating the objects
  will increase reuse and minimize the impact of
  change.

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Key Classes from the Use Case
Homeowner
Motion Detector
Police
Password
Activate_Security Deactivate_Security
Movement_Detected
Notify
Siren
Activate_Siren Deactivate_Siren
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Key Classes after Analysis
Security_Monitor
State
Activate_Security Deactivate_Security
Police
1..n
1
Sensor
Notify
State Type Position
0..n
0..1
Siren
Fire Department
Activated
Activate_Siren Deactivate_Siren
Notify
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Define the Interfaces for the most dynamic areas
Sensor
State Type Position
Activated
Motion Detector
Fire Detector
Door Detector
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Scenario Diagram
Security_Monitor
Sensor
Fire Department
Siren
Activate_Security
Activated
True
Alarm
GetType
Fire
Activate
Notify
Deactivate_Security
Deactivate
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Documentation

• Each Use Case will have a description.
• The description will be using terms from the
  users/clients language.
• Each State Diagram will have a description
• Each Class will have a description.
• Each attribute will have a description.
• Each function will have a description.
• Each Scenario Diagram will have a description.