1. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
Budapest University of Technology and Economics
Xabier De Carlos, Xabier Mendialdua, Salvador Trujillo
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Automated Model Merge
by Design Space Exploration
Csaba Debreceni, István Ráth, Dániel Varró,
1

2. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Collaborative Modeling
2
Alice Bob
Version Control System
Models as files (XMI)
WorkspaceWorkspace
1. Checkout 2. Checkout
3. Local Modifications 5. Local Modifications
4. Commit
CONFLICT

3. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Introducing the Example
3
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Alice
cycle: low
value: 70
A1
A2
cycle: lowA1
value: 70A2
deleteA3
A3

4. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Conflicting Changes
4
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Alice Bob
cycle: lowA1
value: 70A2
:SystemParam
id: TempLimit2
value: 42
cycle: med B1
value: 60 B2
B3
cycle: med B1
value: 60 B2
create B3deleteA3

5. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Phases of Merge Process
 Comparison
o Identifying differences
o Available information:
5
(a) State-based
L
O
R
diffdiff
(b) Change-based
L
O
R
remote
changes
local
changes
diff
(c) Operation-based
L
O
R
remote
op1,op2,...opn
local
op1,op2,...opn
diff

6. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Phases of Merge Process
 Merge
o Integrate different versions
o Available information:
6
L
O
R
remote
changes
local
changes
M
remote
changes
(a) Raw
L
O
R
remote
changes
local
changes
M
(b) Two-way
L
O
R
change’’change’
M
(c) Three-way

7. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Approaches for Model Merge
 Text-based Merge
o UNIX diff, SVN utilities etc.
 Manual Model Merge
o EMF Diff/Merge, EMF Compare
 Semi-automated Model Merge
o AMOR, SIDiff, Westfechtel
 Automated Model Merge
o DSE Merge
7

8. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Modified model
Operation
Initial model
Solution model
Constraints
violated
Goals
satisfied
Design Space Exploration
8
Initial Model
Design Space
Exploration
Candidate
CandidateConstraintsConstraintsConstraints
ConstraintsConstraintsOperations
Candidate
Solution
Global Constraints
Goals
Constraints not violated
Goals satisfied

9. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Overview of the Approach
9
Original
Local
Remote
Comparison
Comparison
Design Space
Exploration
∆L’ ∆R’
Merged
Cemetery
Solution
Solution
SolutionConstraintsConstraintsConstraints
ConstraintsConstraintsOperations
∆L
∆R
∆L
∆R

10. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Initialization of DSE Merge
10
Bob
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2
create B3
MAY
MUST MUST
MAY
MUSTdeleteA3MAY
∆R ∆L
 Annotations for changes:
• MUST – need to be included in a solution
• MAY – can be included in a solution

11. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Initial model
11
Bob
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2
create B3
MAY
MUST MUST
MAY
MUST
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
deleteA3MAY
∆R ∆L

12. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Definition of Operations
12
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2
create B3
MAY
MUST MUST
MAY
MUSTdeleteA3MAY
∆R ∆L
 Operations:
o Default operations
(Create, Delete, Set, Add, Remove)
o Domain-specific operations
• Precondition + Action
Bob

13. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of an Operation
13
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2
create B3
MAY
MUST MUST
MAY
MUST
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
set:A1 set:B1
deleteA3MAY
∆R ∆L
crt:B3

14. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of an Operation
14
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2
create B3
MAY
MUST MUST
MAY
MUST
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
set:A1 set:B1
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
crt:B3
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3

15. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of an Operation
15
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2 MAY
MUST MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
set:A1 set:B1
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3

16. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of an Operation
16
cycle: lowA1
value: 70A2
cycle: med B1
value: 60 B2 MAY
MUST MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
set:A1 set:B1
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3
set:A1
A1
cycle: low

17. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Global Constraints
17
value: 70A2
cycle: med B1
value: 60 B2 MAY
MUST
MAY
Active Operations:
set:B1
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
crt:B3
set:A1
A1
 Global Constraints:
o checked after each step
• Modify a feature that is already modified
• Delete an object already modified
o execution of will violate a global
constraint, thus it has to be disabled
set:B1
B1A1

18. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of DSE Merge
18
value: 70A2
cycle: med B1
value: 60 B2 MAY
MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
set:A2 set:B2
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3
set:A1
A1
cycle: low
del:A3
set:B2
B2
value: 60

19. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Execution of DSE Merge
19
value: 70A2
cycle: med B1 MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3
set:A1
A1
cycle: low
del:A3
set:B2
B2
value: 60
del:A3
A3
[FanAct.]

20. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Goal state and Solution
20
value: 70A2
cycle: med B1 MUST
MAY
Active Operations:
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
crt:B3
set:A1
A1
set:B2
B2
del:A3
A3
[FanAct.]
 Goal State:
o checked after each step
• There are no more executable changes
• (no active operations)
o if it is satisfied, the current state is a solution
o backtrack to find other solutions

21. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Backtracking From Solution
21
value: 70A2
cycle: med B1 MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3
set:A1
A1
cycle: low
del:A3
set:B2
B2
value: 60
del:A3
A3
[FanAct.]
set:A2 set:B1value: 60 B2 MAY
cycle: lowA1MUST

22. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Another Solution
22
value: 70A2
cycle: med B1 MUST
MAY
:WTSystem
:SystemParam
id: TempLimit
value: 100
:SystemOutput
id: FanActivator
:SystemInput
id: Temperature
:WTCtrl
id: CoolingFan
cycle: high
Active Operations:
deleteA3MAY
Completed Set:
Cemetery:
Trajectories:
∆R ∆L
B3
:SystemParam
id: TempLimit2
value: 42
crt:B3
set:A1
B1
cycle: med
del:A3
set:B2
B2
value: 60
del:A3
A3
[FanAct.]
set:A2 set:B1value: 60 B2 MAY
cycle: lowA1MUST
set:B1
set:B2
del:A3
set:B2

23. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Scalability Benchmark
 Synthetic TrainBenchmark
o Supported features
• Model generation
• Fault injection into models
• Reparation of specific faults
 Modified Scalability Benchmark
23

24. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Evaluation Results
 Dimensions
o Model size (10.000-350.000)
o Size of change set (120-960)
o Conflicting changes (0%, 50%, 100%)
 Results
24
 Setup
o (Model Comparison)
o MAY annotations
o Mean execution time of
5 separate runs
MAY

25. BUTE - Fault Tolerant Systems Research Group
IK4-Ikerlan Research Center
MONDO Project
MTA-BME Lendület 2015 Research Group on CPS
Summary
25
Annotate
Changes
• Restrict Design Space
Execute
DSE Merge
• Three-way merge
• State-based
Select
Solution
• Conflict-free models
∆L’
∆R’Merged
Cemetery
MAYMUST
Modified model
Operation
Initial model
Solution model
Constraints
violated
Goals
satisfied
mapping Original ∆L ∆R
Goal and Global const.
Default Operations
Scalability Benchmark
DSE Merge