UML First Pass: Sequence Diagram

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UML First Pass Sequence Diagram
Object
WatchUser
pressButton1()
blinkHours()
pressButton1()
blinkMinutes()
pressButton2()
incrementMinutes()
refresh()
pressButtons1And2()
commitNewTime()
stopBlinking()
Message
Activation
Sequence diagrams represent the behavior as
interactions
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UML First Pass Statechart Diagrams
State
Initial state
Event
button2Pressed
button12Pressed
Blink
Hours
Transition
button1Pressed
button2Pressed
button12Pressed
Blink
Minutes
button1Pressed
button12Pressed
button2Pressed
Blink
Stop
Seconds
Blinking
Final state
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UML Sequence Diagrams

• Used during requirements analysis
• To refine use case descriptions
• to find additional objects (participating
  objects)
• Used during system design
• to refine subsystem interfaces
• Classes are represented by columns
• Messages are represented by arrows
• Activations are represented by narrow rectangles
• Lifelines are represented by dashed lines

TicketMachine
Passenger
selectZone()
insertCoins()
pickupChange()
pickUpTicket()
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UML Sequence Diagrams Nested Messages
ZoneButton
TarifSchedule
Display
selectZone()
lookupPrice(selection)
price
displayPrice(price)
Dataflow
to be continued...

• The source of an arrow indicates the activation
  which sent the message
• An activation is as long as all nested activations

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State Chart Example
Waiting
Requests finished (no further requests)
Button press (other floor)
Button press (same floor)
Arrival at a request floor
Moving
Service floor (open doors)
Button press
Sample State Chart for an Elevator class