Incorrect use-case diagram
User
Administrator
Login
Backup Database
Create Profile
Save Profile
Delete Profile
How many errors are in this diagram?
Use Cases Whats Wrong
• Comment on these use cases in the
discussion forum Use Cases what is
wrong
This implies that both the
administrator and the
User are needed for this
use case.
Incorrect use-case diagram
User
Administrator
Login
Backup Database
Create Profile
Save Profile
Delete Profile
How many errors are in this diagram?
This implies a sequence
of use cases. Either an
extend or include not a
sequence.
Incorrect use-case diagram
User
Administrator
Login
Backup Database
Create Profile
Save Profile
Delete Profile
How many errors are in this diagram?
Must be associated with
an actor or another use
case..
Incorrect use-case diagram
User
Administrator
Login
Backup Database
Create Profile
Save Profile
Delete Profile
How many errors are in this diagram?
Use Case Diagrams
require a boundary.
Incorrect use-case diagram
User
Administrator
Login
Backup Database
Create Profile
Save Profile
Delete Profile
How many errors are in this diagram?
Errors in the use-case diagram
•
Do not use use-cases to show sequence of actions
–
•
•
•
•
For example, you first do login, then create profile, then save profile.
Use sequence or activity diagrams instead
Only show two or more actors are involved in the use case, if all
actors are needed in the process. For example, does a user really
need an administrator when doing a login?
For use cases, arrows between actors and use-cases should be
bi-directional
Use- cases should always have an actor associated with it, even
for autonomous systems (Unless the use case is part of a
<<includes>> or <<extends>> relationship, then one of the usecases will not need an actor associated with it.)
If you have a relationship between two use-cases, remember to
show the relationship as <<extends>>, <<includes>>, etc
Correct use-case diagram
Login
User
Delete Profile
Librarian
Create Profile
Administrator
Backup Database
Use Case Diagram
Generate
Student
Transcript
1
Student
<<Included>> in use
cases 1,2,4,5,7
Login
10
1
Change
Curriculum
year
4
Staff
Generate
Recommendations
5
2
Notify
Students of
Curriculum
Change
<<extends>>
6
3
Change
Curriculum
2
<<extends>>
Store
Curriculum for 6
years
3
5
4
Create Class
Schedules
7
How many errors are in this diagram?
Student Advising System
11. Compute
Possible courses
<<includes>>
12. Display/Print
suggested courses
*
<<includes>>
10. Retrieve
Course Offerings
*
Student
<<includes>>
9. Compute
Remaining Requirements
<<includes>>
4. Retrieve
Completed Courses
<<includes>>
7. Select Enrolled
Courses not expected to
complete
*
<<includes>>
5. Retrieve
courses in progress
<<includes>>
*
<<includes>>
8. Select current or
original curriculum
*
*
<<includes>>
Enrolled Student
6. Enter courses
completed at another
institution
*
*
3. Login
Prospective Student
<<includes>>
1. Create/Update
Curriculum
<<includes>>
*
*
*
Academic Dept Staff
2. Create/Update
course substitution rules
*
How many errors are in this diagram?
How many errors are in this diagram?