Using SUCD to Describe Use Cases

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Using SUCD to Describe Use Cases

• ECE 621

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Authoring Styles

• Many authoring styles exist
• Tailored for specific domains
• Real-Time systems
• Safety critical systems
• Most authoring styles use templates
• Overwhelming majority only use unstructured
  natural language
• Very little structure

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SUCD

• Provides rigor
• Helps clarify the flow of use cases
• Helps avoid common mistakes
• Can be used to automatically generate the
  corresponding use case diagrams, hence ensures
  consistency

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Headers an actions
Actions
The Actor

• BEGIN enter member information
• Librarian? enters members name
• Librarian? enters members address
• Librarian? enters members phone number
• END enter member information

The Same
A Header
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Basic Flow

• BEGIN Use Case
• Headers and Actions
• .
• END Use Case

Reserved only for the Basic Flow
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Alternative Flow
The Header in the Basic Flow

• AT enter ticket order information
• PERFORM search tickets
• IF tickets not available
• Headers and Actions

The action in that header from the Basic Flow
The condition
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Subflows
Subflow name

• SUBFLOW print receipt
• BEGIN print transaction information
• SYSTEM? prints Customer information
• SYSTEM? prints team hockey card information
• SYSTEM? print items information and total price
• END print transaction information

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Extension Points At The Base Use Case

• Extension Points
• PUBLIC EXTENSION POINT
• Grand Prize Giveaway

Name of the extension point
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Extension Points At The Extension Use Case
Name of the extended UC

• PUBLIC EXTENSION POINT BEHAVIOR
• EXTENDING Buy Team Merchandise Grand Prize
  Giveaway
• FLOW Basic Flow
• AT a chance to win
• IF winning ticket was entered
• BEGIN grand prize giveaway
• SYSTEM? notifies Customer the he/she won the
  grand prize
• Customer? enters phone number for a Customer
  service representative to call
• END grand prize giveaway
• CONTINUE END Use Case

Name of the extension Point
The flow inside the base UC
Where to continue at base UC
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Abstraction, Implementation and Specialization

• Keywords used in the Name section
• ABSTRACT
• IMPLEMENTS
• SPECIALIZES

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More Keywords (2)

• INCLUDE to perform an inclusion UC
• PERFORM to performed a Subflow
• RESUME what to perform next
• AFTER what needs to be performed first
• AT/IF what condition to evaluate and where
• BEGIN/END
• PUBLIC EXTENSION POINT at the base UC
• PUBLIC EXTENSION POINT BEHAVIOR at the
  extension UC
• PRIVATE EXTENSION POINT private to the UC
• FLOW which flow in the base UC
• CONTINUE where to go back in the base UC