1. UML: State Chart Diagrams
Sabbir Muhammad Saleh
SAD ::: Fall ::: 2015

2. Statechart Diagrams
difference between Statechart diagrams and Activity diagrams:
Statechart diagrams are used to represent a single object and how its behavior causes it to change state
Activity diagrams are used to model how different areas of work behave with each other and interaction

3. Statechart Diagrams: Components
a statechart diagram is composed by three components:
- state
- transitions
- events

4. Statechart Diagrams: What’s “State”
state is defined as a snapshot or a milestone of an object’s behavior at a particular point in time on
Computer
booting
processing
can be in the following states:
idle
Shutting down
off

5. Statechart Diagrams: Components – State
there are three separate notations for states in the statechart diagram:
State
State
Start State
End State

6. Statechart Diagrams: Components – State
a statechart diagram can include zero or more start states
a statechart diagram can include more than one end states

7. Statechart Diagrams: Components – Transitions
transitions are used to show flow from one state to another
State A
State B

8. Statechart Diagrams: Components – Decision Points
decision points make the diagram more visually appealing by grouping transitions
State A
State B
State C

9. Statechart Diagrams: Components – Synchronization
synchronization bars are used to show where states need to catch up with or wait up for others
State A
State B

10. Statechart Diagrams: Components – Actions and Events
actions and events are used to describe how states are reached, what happen when they are reached, and what happen when they are exited

11. Statechart Diagrams: Components – Actions and Events
events are indicated directly on the path of a transition from a state to another state
Reset
Deleted
Cancel
Data Entered
Clean
Dirty
Continue
Saved
New

12. Statechart Diagrams: Components – Actions and Events
an action shows what behavior happens when an event occurs, there are five basic action types:
- entry (action that occurs when state has been entered)
- exit (action that occurs when state is being abandoned)
- do (action that occurs when state is being occupied)
- include (invokes a submachine)
- event (used to specify the action that occurs when a specific event is fired)

13. Statechart Diagrams: Components – Actions and Events
Exit / Reset
Deleted
Cancel / EmptyData()
Data Entered / RecordData()
Clean
Dirty
Continue / SaveData()
Saved
Exit / Reset

14. Statechart Diagrams: Components – SubStates
used to model hierarchical states
Event A
[condition 1]
Event A
[condition 2]
Event A
State A
State A
State 1
State 2

15. Statechart Diagrams: Components – Composite States
used to model hierarchical states
State B
State A
State 1
State 2

16. Statechart Diagrams: how to build models
there are five steps
- identify the entities (objects or use cases) that
need to be further detailed
- identify the start and end states for each entity
- determine the events relating to each entity
- create the statechart diagram beginning with
the start event
- create composite states where necessary