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Object-Oriented Modeling
Using UML: Dynamic Models
CS 3331
Dynamic Behavior
• What happens when the program runs
• How do states of objects change
• How do objects interact with each other
• How is data transformed
Use case diagram
• Describes the externally observable
behavior of system functions, usually to
define system requirements
• Describes interactions between the
system and external entities
Example: Goldmine
Check
Grades
Register
actor
system
boundary
use case
Validate User
<>
Student
Elements of Use Case Diagram
• Actor:
• Use case:
• Relationship:
Example: Goldmine (Cont.)
<>
User
Student
Faculty
Enter Grades
Validate User
Check Grades
Get Roster
Register
<>
<>
User
Student Faculty
Use Case Scenarios
Use Case: Check Grades
Description : View the grades of a specific year and semester
Actors : Student
Precondition : The student is already registered
Main scenario:
User System
- The user enters the year and
semester, e.g., Fall 2006.
- The system carries out “Validate User”.
- The system prompts for the year and semester.
- The system displays the grades of the courses
taken in the given year and semester.
Alternative :
The student enters “All” for the year and semester, and the system displays
grades of all courses taken so far.
Exceptional:
The “Validate User” use case fails; the system repeats the validation use case.
Interaction Diagrams
• 4 types
– Sequence Diagrams
– Communication Diagrams
– Interaction Overview Diagram
– Timing Diagram
Sequence diagram
• Depicts object interaction by highlighting
the time ordering of method invocations
• Describes a sequence of method calls
among objects
Example
: Customer : Order : Payment : Product : Supplier
place an order
process
validate
deliver
if ( payment ok )
back order
if ( not in stock )
get address
mail to address
message
lifetime
control
object
sdPlaceOrder
Example (Cont.)
: Customer : Order : Payment : Product : Supplier
place an order
process
validate
deliver
if ( payment ok )
back order
if ( not in stock )
get address
mail to address
Sequence of message sending
Sequence Diagram
sdPlaceOrder
:CustomerWIndow :Customer
Change
Update
Transitions
• Lead from one state to another
• Instantaneous
• 4 types of events:
Statechart Diagram
• Graph representing finite state machine
• Network of states and transitions
• Good for modeling reactive systems
Elements of Statechart
Idle Running
Definition
• Event
- An occurrence of a stimulus that can trigger a state
transition
- Instantaneous: no duration
Simple Phone Example
dial digit(n)
[incomplete]
Dialing Connecting
busy
connected
dial digit(n)
[valid] / connect dial digit(n)
[invalid]
Invalid
Ringing
Busy
Another Example
anomaly
Normal
Recovery
Identification
Pressure
Recovery
Temperature
Recovery
recovery success
recovery success
recovery
success
anomaly=
temperature
anomaly=
pressure
recovery failure
recovery
failure
recovery
failure
Composite States
anomaly
Normal
Recovery
Identification
Pressure
Recovery
Temperature
Recovery
recovery
success
done
done
temperature pressure
Recovery
recovery
failure
Composite States (Cont.)
• Used to simplify diagrams
• Inside, looks like statechart
• May have composite transitions
• May have transitions from substates
• Sequential and parallel
Composites and Transitions
Idle
Maintenance
Printing
Selecting Processing
Validating
Transition from substate
Including Composite States
Start
entry / start dial tone
exit / end dial tone
Partial Dialing
entry / number.append(n)
digit(n)
digit(n)
[number.isValid()]
Dialing
Dial Number
Include / Dialing
