www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 2
!"#$%#
!!
on what?
on what?
why
why
?
?
how
how
?
?
who
who
?
?
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 3
&
'
'
##(###
##(###
#
#
#$%#)
#$%#)
* +#,#-#).)/
0%#(
0%#(
Risk
identification
Risk
assessment
Risk
control
##.
##.
,).
,)
1#
-##/.
#$
(,
(,
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 4
#$#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 5
$#$$#
$#$$#
*
$#2
* $#
*
3$##
$#
$#
*
3$#
*
3$#
* 4$#564
* $#
3$#$
3$#$
* 7$#
*
)$#
* )$#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 6
$#2
).
).
$)$#
$)$#
-
$)/
3$#
3$#
'
'
#)
#)
#
#
-/
-/
•
{
O
O, Dom } |= not
obstruction
•
{
O
O, Dom } |≠ false domain consistency
8
3
#$$$)feasibility
G: TrainStoppedAtBlockSignal
If
If StopSignal
Dom:
If
If TrainStopsAtStopSignal
then
then DriverResponsive
O: Driver
Un
Unresponsive
9$)1#
9$)1#
$$)-
$$)-
)
)
#/
#/
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 7
$#
7.$#$#
7.$#$#
{not O
1
, , not O
n
, Dom } |=
domain completeness
If
If
not
not DriverUnresponsive
and
and
not
not BrakeSystemDown
and
and StopSignal
then
then TrainStoppedAtBlockSignal
$4##
$4##
$$$((($:
$$$((($:
3$##)
3$##)
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 8
3$####
#+
#+
Hazard
Hazard
$#$#
$#$#
Safety
Safety
Threat
Threat
$#$#
$#$#
Security
Security
–
Disclosure, Corruption, DenialOfService,
Inaccuracy
Inaccuracy
$#$#
$#$#
Accuracy
Accuracy
Misinformation
Misinformation
$#$#
$#$#
Information
Information
–
NonInformation, WrongInformation, TooLateInformation,
Dissatisfaction
Dissatisfaction
$#$#
$#$#
Satisfaction
Satisfaction
–
NonSatisfaction, PartialSatisfaction, TooLateSatisfaction,
Unusability
Unusability
$#$#
$#$#
Usability
Usability
Us
ability
Convenience
Goal
Functional goal
Non-functional goal
Quality of service
Compliance
Architectural
Development
Confident
i
ality
Integrity
Availability
Distribution
Installation
Safety
Security
Performance
Reliability
Maintainability
Cost
Time
Space
Deadline
Variability
Software
interoperability
Interface
User
interaction
Device
interaction
Satisfaction
Information
Stim-Response
Accuracy
Cost
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 9
$#$$#
$#$$#
*
$#2
* $#
*
3$##
$#
$#
*
3$#
*
3$#
* 4$#564
* $#
3$#$
3$#$
* 7$#
*
)$#
* )$#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 10
3$#56;3
#
#
-/
-/
*
'not
* $#
56
564.
3
34#
*
$#$..
obstruction
TrainStoppedAtBlockEntry
If StopSignal
StopSignal And
Not TrainStoppedAtBlockEntry
SignalNotVisible
DriverUnresponsive
BrakeSystemDown
…
root obstacle
OR-refinement
ResponsivenessCheck
SentRegularly
resolution
countermeasure goal
obstacle
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 11
3$#56;3-</
MobilizedAmbulance
AtIncidentInTime
MobilizedAmbulance Not
AtIncidentInTime
AmbulanceLost
AmbulanceStopped
TrafficDeviation
…
AmbulanceCrew
NotInFamiliarArea
AND-refinement
In-carGPS
NotWorking
…
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 12
3$#
56
56
4$#
4$#
3
3
$
$
*
#{subO
1
, , subO
n
, Dom } |=
3
*
#{subO
1
, , subO
n
, Dom } |≠ false
*
{subO
1
, , subO
j-1
, subO
j+1
, , subO
n
, Dom } |=
3
3
3
4$#
4$#
3
3
$
$
*
{subO
i
, Dom } |=
3
*
4#{subO
i
, Dom } |≠ false
*
4#{not subO
1
, , not subO
n
, Dom } |= not
3
*
%{subO
i
, subO
j
, Dom } |= false
7
7
subO
subO
i
i
34
34
3
3
3
3
$#
$#
subO
subO
i
i
$#
$#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 13
3$#$4
564
6=(
6=(
not
not
-!
-!
and
and
</
</
,)
,)
not
not
!
!
or not
or not
<
<
'>
)
#,#
#,#$##$
4)$#
G
propagated
obstruction
G1
G2
not G1
not G2
not G
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 14
$#
Obstacle DriverUnresponsive
Def Situation of a train driver failing to react to a command
and take appropriate action according to that command
? FormalSpec in temporal logic for analysis,
not
not in this chapter @
? Category Hazard @
? Likelihood likely @
? Criticality catastrophic@
DriverUnresponsive
#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 15
$#$$#
$#$$#
*
$#2
* $#
*
3$##
$#
$#
*
3$#
*
3$#
* 4$#564
* $#
3$#$
3$#$
* 7$#
*
)$#
* )$#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 16
3$#
#$
#$#
#$#
⇒ #.
(#$#
⇒#.#
3$#
3$#
9#
9#
* $#$A
* +)A
* )##+)
'>
(#
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 17
3$#$
(
Goal model
elaboration
data dependency
Obstacle
identification
Obstacle
assessment
Obstacle
resolution
4$#($##$
4$#($##$
* ##$#,#
##2
##2
*
-,1#/(((
(-B4/
*
$0+-CD.#./
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 18
7$#
9$##
9$##
-..#/
-..#/
A
A
E'>$#F
E'>$#F
56;3
56;3
not
not
)()
)()
E##1)F
E##1)F
#$##(
#$##(
$..).)$
$..).)$
'
'
4#
4#
##
##
4
4
Obstacle
identification
Obstacle
assessment
Obstacle
resolution
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 19
7$#
4$
'>
'>
)
)
not
not
(A
(A
and
and
B)
B)
not
not
A
A
or
or
not
not
B
B
not
not
(A
(A
or
or
B)
B)
not
not
A
A
and
and
not
not
B
B
not
not
(
(
if
if
A
A
then
then
B)
B)
A
A
and
and
not
not
B
B
not
not
(A
(A
iff
iff
B)
B)
(A
(A
and
and
not
not
B)
B)
or
or
(
(
not
not
A
A
and
and
B)
B)
'>
'>
#34(
#34(
4##)
4##)
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 20
7$#$4$
MotorReversed Iff MovingOnRunway
MotorReversed
Iff WheelsTurning
MovingOnRunway
Iff WheelsTurning
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 21
7$#$4$
NOT
MovingOnRunway
Iff WheelsTurning
NOT
MotorReversed
Iff WheelsTurning
$#
MotorReversed Iff MovingOnRunway
MotorReversed
Iff WheelsTurning
MovingOnRunway
Iff WheelsTurning
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 22
7$#$4$
NOT
MovingOnRunway
Iff WheelsTurning
NOT
MotorReversed
Iff WheelsTurning
MotorReversed
AndNot
WheelsTurning
$#
34
-#/
WheelsTurning
AndNot
MotorReversed
MovingOnRunway
AndNot
WheelsTurning
WheelsTurning
AndNot
MovingOnRunway
MotorReversed Iff MovingOnRunway
MotorReversed
Iff WheelsTurning
MovingOnRunway
Iff WheelsTurning
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 23
7$#$4$
NOT
MovingOnRunway
IffWheelsTurning
NOT
MotorReversed
IffWheelsTurning
MotorReversed
AndNot
WheelsTurning
Aquaplaning
$#
34
-#/
WheelsTurning
AndNot
MotorReversed
MovingOnRunway
AndNot
WheelsTurning
WheelsTurning
AndNot
MovingOnRunway
WheelsNotOut
WheelsBroken
MotorReversed Iff MovingOnRunway
MotorReversed
Iff WheelsTurning
MovingOnRunway
Iff WheelsTurning
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 24
3$##1
BrakeReleased ↔ DriverWantsToStart
BrakeReleased
↔ MotorRaising
MotorRaising ↔
AccelerPedalPressed
AccelerPedalPressed
↔ DriverWantsToStart
www.wileyeurope .com/college/van lamsweerde Chap.9: Risk Analysis on Goal Models © 2009 John Wiley and Sons 25
MotorRaising And Not
AccelerPedalPressed
3$##1
BrakeReleased ↔ DriverWantsToStart
BrakeReleased
↔ MotorRaising
MotorRaising ↔
AccelerPedalPressed
AccelerPedalPressed
↔ DriverWantsToStart
AccelerPedalPressed
And Not DriverWantsToStart