UML use case diagram implementation

Automatically layout use case diagrams from structured input. This is VERY useful in solution architecture.

This issue involves all conceptional work, that is needed to find a practical input format.

UML Use Case Diagrams.

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1. Actor Notation

• Shape: Stick figure
• Placement:
  • Always outside the system boundary
• Inheritance:
  • Solid line with hollow triangle
  • Triangle points to the parent actor

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2. Use Case Notation

• Shape: Oval (ellipse)
• Placement:
  • Always inside the system boundary
• Inheritance:
  • Solid line with hollow triangle
  • Triangle points to the parent use case

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3. System Boundary

• Shape: Rectangle
• Contents:
  • Only use cases are allowed inside
• Actors:
  • Never placed inside the boundary

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4. Association (Actor ↔ Use Case)

• Line type: Solid line
• Arrowhead: None (by default)
• Connection:
  • Actor ↔ Use Case only

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5. «include» Relationship

• Line type: Dashed line
• Arrowhead: Open arrow
• Direction:
  • From base use case → included use case
• Label:
  • «include» (with guillemets)
  • Placed near the line
• Connection:
  • Use Case → Use Case only

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6. «extend» Relationship

• Line type: Dashed line
• Arrowhead: Open arrow
• Direction:
  • From extending use case → base use case
• Label:
  • «extend»
• Optional:
  • Extension point name in brackets (rarely shown)

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7. Generalization (Inheritance)

Applies to actors and use cases.

• Line type: Solid line
• Arrowhead: Hollow triangle
• Direction:
  • Child → Parent
• Label: None

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8. Visual Legend (Quick Reference)

Element	Shape	Line	Arrow
Actor	Stick figure	—	—
Use Case	Oval	—	—
System	Rectangle	—	—
Association	—	Solid	None
«include»	—	Dashed	Open
«extend»	—	Dashed	Open
Generalization	—	Solid	Hollow triangle

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