This is my Basic Understanding of UML Use Case Diagrams. Highlights the Notations, Terminologies & its description, with an example.

1. Use Case Diagrams
• Harish Alwala

2. Words to know
• Use case
• Actor
• <<extend>>
• <<include>>
• Generalization & Specialization

3. What does each mean?
• Use Case:
– Use cases are descriptions
of the functionality of the
system from users’
perspective.
– Use case diagrams, like
sequence diagram,
collaboration diagram &
Activity Diagram, in UML
are diagrammatical
representation of the
requirements of the system
from users’ perspective.
– They also define scope of
requirements.

4. What does each mean?
• Actor:
– Actor represent the role that take on when
communication with particular use cases in the system
– An Actor initiates process.
– An Actor can be a person, devise or system

5. What does each mean?
• <<extend>>
– A Stereotype used to show the use case that
provides additional functionality that may be
required in another use case.
– Eg:
• Print Summary use case is extension for Display
summary use case
• Display supplementary card summary use case
for Display Basic card summary use case

6. What does each mean?
• <<include>>
– A Stereotype used when there is a sequence
of behavior that is used frequently in a
number of use cases
– Eg:
• Find Book is common use case used to Check
Availability use case and Book for future use
case in Library computerization system
• Identify Requester is common use case used to
Penalize Student & Issue A Book use case

7. What does each mean?
• Generalization & Specialization:
– The generalization link is an informal way of showing that one
use case is similar to another use case, but with a little bit of
extra functionality.
– One use case inherits the functionality represented by another
use case and adds some additional behavior to it.
– Eg:
• Two actors, Staff Contact and Campaign Manager and a
Campaign Manager can do everything that a Staff Contact can do,
and more.
• Campaign Manager use case is a specialization of Staff Contact
• Inheritance functionality of Campaign Manager over Staff Contact
is Generalization.

8. Extension…
Manage Team
Do Coding
End to End
Project Management
Billability Mgmt
PM
TL

9. Example
• Library Computerization
– Format to document each Use Case
• Name of the Use Case
• Pre-Condition
• Post Condition
• Purpose
• Description
• Use Cases Diagrams

10. Example
• Name of the Use Case
– Student / Staff
• Register to Library
• Search for the required book
• Book Reservation
• Check for availability
– Staff
• Suggest to buy a book
– Administrator
• Organize books
• Organize Library Registered members
• Issue books
• Penalize the user
• Raise invoice for new books