2. Statechart Diagram
- Bersifat dinamis
- Memperlihatkan state-state pada sistem;
memuat state, transisi, event, serta
aktivitas.
- Memperlihatkan sifat dinamis dari
antarmuka, kelas, kolaborasi dan terutama
penting pada pemodelan sistem-sistem
yang reaktif
3. SYSTEMS ANALYSYS AND DESIGN METHODS 5TH Edition Whitten Bentley Dittman
Membuat model behavior dari objek-objek
• Setiap objek dapat dikatakan memiliki state ---
nilai dari attributnya pada suatu saat tertentu.
• State diagram memodelkan daur hidup sebuah
objek tunggal. Ia menggambarkan macam-
macam state yang dimiliki sebuah objek, event
yang mengakibatkan perubahan state selama
waktu tertentu dan aturan-aturan yang mengatur
transisi objek antara satu state dengan state
lainnya.
• Perubahan terhadap state objek terjadi ketika
ada suatu kejadian atau ketika nilai dari salah
satu atributnya berubah. Perubahan state ini
dipicu oleh adanya suatu event.
Irwin/McGraw-Hill Copyrighth@2000 The Mcgraw-Hill Companies All Right reserved
4. Developing Software Woth UML Booch Jacobson Rumbaugh
• Sebuah state diagram menunjukkan urut-urutan state
dari sebuah objek selama masa hidupnya / lifetimenya,
sekaligus dengan event-event yang menyebabkan
perubahan dari state tersebut.
• Sebuah state diagram menjelaskan sebuah hypothetical
machine (finite automaton) yang pada setiap waktu
berada pada satu set finite state, yang terdiri dari:
• a finite, non-empty set of states;
• a finite, non-empty set of events;
• functions, yg menjelaskan transisi dari satu state ke
state berikutnya;
• sebuah initial state;
• satu set final state.
Addison-Wesley
5. Developing Software Woth UML Booch Jacobson Rumbaugh
Soal:
• On opening the flight, the initial state leads to the NoReservation
state. When the state is entered, the Reset operation is executed. If
a reservation is made for this flight, the object changes to the state
PartiallyReserved.
• The Reserve event is associated to the homonymous Reserve
action (implemented as an operation).
• In this operation, the actual reservation takes place, and the internal
reservation counter is updated. After termination of this action, we
will find the object in the PartiallyReserved state.
• Each additional reservation leads to the same action. As long as a
free seats are available, the object remains in the PartiallyReserved
state. If only one seat left, it changes into FullyBooked state.
Cancellation of reserved seats is carried out in a similar way. Thus,
the state diagram describes which actions are triggered by which
events and under which conditions these (and together with the call
of the corresponding operations) are permitted.
Addison-Wesley
7. Developing Software Woth UML Booch Jacobson Rumbaugh
State
• Sebuah state dimiliki oleh satu buah Class dan
merepresentasikan abstraksi atau kombinasi dari
satu set nilai atribut yang mungkin terjadi pada
objek tersebut dari class ini.
• Tidak setiap perubahan nilai atribut akan dianggap
sebagai perubahan state. Hanya event tertentu
yang sangat signifikan mengakibatkan perubahan
behavior dari objek.
• Sebuah state oleh karena itu dapat dilihat juga
sebagai rentang waktu (time span) antara dua
event.
• Dua type khusus state yang ada adalah initial state
dan final state.
Addison-Wesley
8. Developing Software Woth UML Booch Jacobson Rumbaugh
• Tidak ada transisi yang menuju initial state dan tidak ada
event yang diperbolehkan meninggalkan final state.
• Transisi dari satu state ke state berikutnya di trigger /
dipicu oleh event. Sebuah event terdiri dari nama event
dan sejumlah argument.
• Event dapat memicu aksi didalam state yang dilakukan
melalui operasi tertentu.
Ada tiga trigger yang sudah predefine:
• entry, fires automatically when entering a state
• exit, fires automatically when leaving a state
• do, fires repeatedly as long as the state is active, that is,
not left.
Addison-Wesley
9. Developing Software Woth UML Booch Jacobson Rumbaugh
Substate
• Sebuah state dapat diuraikan lebih lanjut, baik
sekuensial ataupun paralel substate.
• Gambar dibawah ini menunjukkan sebuah sequential
nesting. Ketika kontrak asuransi ditetapkan, sebuah
produk dipilih (sebagai contoh, content-nya), yang terdiri
dari beberapa produk element (Pel), seperti furniture,
gelas, dsb. Untuk setiap produk elemen, sebuah cover
(istilah asuransi) harus dibuat. Ilustrasi dibawah ini
menunjukkan Create covers state dari context ini.
Create Covers
covers:set=Empty set
PElQuantity Define
Reset cover
addPEl [isComplete]
addPEl
Addison-Wesley
10. Developing Software Woth UML Booch Jacobson Rumbaugh
Gambar dibawah ini menunjukkan notasi
dari paralel substates.
substates
event1
S3
S4
S1 S2
event2 event3
event4 S5
Addison-Wesley
11. Developing Software Woth UML Booch Jacobson Rumbaugh
Event dan transition
• Sebuah event adalah sebuah kejadian yang
memiliki pengaruh khusus dalam suatu context yang
dibicarakan, karena ia men-trigger / memicu
perubahan state.
• Kebalikan dari state, event bukan milik satu kelas
tertentu.
• State transition (perubahan state) biasanya dipicu
oleh adanya event yang digambarkan dengan anak
panah yang menghubungkan state satu dengan
state lainnya.
Addison-Wesley
13. Transitions
event [guard] | action
x
x y
y
The action that
takes place when
The event that Conditions that the transition is
triggers the must be met for taken
transition the transition to
take place
14. Transitions
event [guard] | action
x
x y
y
The action that
takes place when
The event that Conditions that the transition is
triggers the must be met for taken
transition the transition to
take place
15. Events
• General Events
– Method calls: received(customer)
– Event signals: inventoryReady
created
created
• Time event
– interval expiry; inventoryReady
tm(3 days), tm(1000 ms)
– calendar/clock time; when(11:50) in gathering
in gathering
• Change Event:
false(hasProblems)
– Change in value of some entity;
false(hasProblems) sent
sent
true(hasProblems) tm(3 days)
received()
is received
in problem
16. Guards (Conditions)
gatheringFinished [all items were gathered]
sent
sent
in gathering
in gathering
in problem
in problem
gatheringFinished [items are not found]
• Boolean expressions.
• Evaluated when the transition is triggered
• Types of guards:
– Simple predicate: [hasProblems], [x > 0]
– Combined predicates:
[¬hasProblems ∨ (hasProblems ∧ order.sum < 100]
– Guards on activities: [active(gatherItems)]
– State related (we’ll get back to it later)
17. Guards - Example
bid [value < 100]
bid [value >= 200]
Selling Happy
bid [(value >= 100) AND (value < 200)]
Unhappy
Intro | Building Blocks | Advanced
18. Static Conditional Branching
• A graphical shortcut for convenient
rendering of decision trees
Selling Happy
bid
[value >= 200]
[value < 100]
[(value >= 100) & (value < 200)]
Unhappy
19. Empty Transitions
• A transition can have any combination
(including none) of the events, guards and
actions
Empty
• When a transition does not have an event,
Employee Transition
it is taken after all the activities were
rest[break] Cleaning
ended
Working do: put water
do: put soap doing nothing
do: shovel work do: wash soap
do: drain
work
20. Guards and Events
• What’s the difference between the two
machines?
E1 true(C)
S1 S2 S3
E1 [C]
S1 S2 S3
What happens if C changes to True
before E1?
21. Actions
• An executable atomic computation
• Types of actions
– Variable assignment:
received() | status := received
sent
sent is received
is received
– Throwing a signal:
received() | throw(InventoryUpdate)
sent
sent is received
is received
– Start, or stop activities (and concatenation of actions):
| start(sendBill); stop(delivery); x := x+1
sent
sent is received
is received
22. Transitions - advanced
• Self-transitions: Transitions can be directed to the same
state: / c=0
S2 E1 / c:=c+1
• Un-deterministic states – when two transitions are taken
in the same time, one of will be taken in an un-
deterministic fashion:
E1
S1 S2
[C1]
S3
23. How does a Washing Machine Works?
• On / Off button. Start button
• (No stop button.)
• Feedback is given on the current stage
(soaking, rinsing, draining, drying)
• Three plans:
– Regular
– Delicate (no soaking)
– Super delicate (no soaking, no drying)
• Off can be clicked only before starting, or
after finishing
25. State Explosion: An Example
What is the off
button can be
clicked at any time?
What if we want to show
how many minutes left
to the end of the cycle?
What if we want to
come back to the
same state we left?
26. Abstraction in Statechart
Separating Independent
Finding Common Regions
Behavior
Composite States Parallel States
27. The State Explosion Problem
Class Class Class
v1 : {t, f} v1 : {t, f} v1 : {t, f}
v2 : {t, f} v2 : {t, f} v2 : {t, f}
v3 : {t, f}
...
v3 : {t, f}
... ... v3 : {t, f}
...
• Let
– n: Num of Classes
– m: Num of variables (assume equals among classes)
• Number of possible states = 2(nm)
• And...
– What if the state space of each variable > 2
– What about association between objects?
29. Composite + History
off
click(power)
click(power)
On
H
idle Tm(10 mins) | light(off)
click(start) [plan=regular]
soak
click(start) [plan=delicate
Do: light(soak)
or super delicate]
Do: pump(in)
Tm(5 mins) [plan=super delicate] | light(off)
tm(30 mins)
rinse drain dry
tm(5 mins)
Do: light(rinse) tm(30 mins) Do: light(drain) [plan=not super Do: light(dry)
Do: stir() Do: pump(out) delicate] Do: stir()
30. deep and shallow
Shift ended | clh()
Stop
pause
Diagnosing
return
H Diagnostic1
Diagnostic1 Diagnostic2
Diagnostic2
return-full
H* setup
setup Find a vein
Find a vein
clh() – clears Check blood
Check blood
Draw Blood
Draw Blood
the history pressure
pressure
31. Completion Transitions
• Triggered by a completion event
– generated automatically when an immediately nested state
machine terminates
Committing completion
transition (no trigger)
Phase1
Phase1
Commit Done
Phase2
Phase2
32. Triggering Rules
• Two or more transitions may have the same event trigger
– inner transition takes precedence
– if no transition is triggered, event is discarded
LampFlashing
FlashOn
FlashOn
on/
on/ off/
FlashOff
FlashOff
33. Order of Actions: Complex Case
• Same approach as for the simple case
S1 S2
exit:exS1 entry:enS2
| initS2
S11 E/actE S21
exit:exS11 entry:enS21
Actions execution sequence:
exS11 exS1 actE enS2 initS2 enS21
34. Parallel States
• Sometimes, some aspect of an entity are independent of other
aspects
Martial employee
single
Staff
Member
married
Manager
divorced
35. Parallel States Annotation
• Martial
Combine multiple simultaneous employee
descriptions
single
Staff
Member
married
Martial employee
single Manager
divorced
Staff
Member
married
divorced Manager
Intro | Building Blocks | Advanced
36. Interactions Between Parallel
States off
click(power)
click(power)
On H
idle Spin Slow
Do: spin(150rpm)
click(start) idle
[Plan in Regular]
Regular
Tm(entered(rinse),15)
Tm(30) Exited(rinse)
click(start) soak Entered(rinse)
[Plan in
[Plan not in Regular] click(plan)
Super Delicate] Entered(rinse)
[Plan not in Regular] idle
out
Tm(30)
Tm(30) click(plan)
Entered(soak) Do: pump out Delicate
water Entered(drain)
Exited(drain)
rinse
click(plan)
in
Tm(30)
[Plan not in Super Delicate] Super Spin Fast
Do: pump in
Delicate
water
Do: spin(400rpm)
drain
Controller Pump Plan Rotor
37. “Flat” and Parallel Machines
• Every parallel machine can be transformed into a
sequential machine:
A D µ
E
B Use of
γ δ F Orthogonal
α β
(in G) α Regions
C G
µ δ
B,F
γ
B,E B,G
α α β No Use of
α Orthogonal
γ
C,E
α C,G Regions
µ C,F δ
38. Transition Forks and Joins
• For transitions into/out of orthogonal
shipping
regions:
Processing
Processing Sent
Sent Confirmed
Confirmed
Credit Card
Credit Card [ok]
verification
verification Receipt Sent
Receipt Sent
fork [not ok] charging Join
In problem
In problem
