held by Wil van der Aalst at the BPM 2010 conference in Hoboken, NY.

1. Correctness Ensuring
Process Configuration:
An Approach Based on
Partner Synthesis
Wil van der Aalst (TU/e, QUT)
Niels Lohmann (U-Rostock, TU/e)
Marcello La Rosa (QUT)
Jingxin Xu (QUT)

2. The need for configurable process
models: CoSeLoG project
+/- 430 Dutch
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municipalities

3. The need for configurable process
models: Suncorp case
End to end process has between 250-1000 process steps
Product
Sales Service Claims 500
Dev steps
• 25+ steps • 50+ steps • 75+ steps • 100+ steps
Sources: Guidewire reference models, GIO CISSS Project, CI US&S P4PI Project
Home      
Motor         30
Commercial      variations
Liability     
CTP / WC     
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4. Two variants of the same process …
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5. Variation points
Configuration = limiting behavior !
Activate
Hide/skip
Block
Blocking Hiding Blocking
Action
Activating
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6. Correctness of configurations
+ =
Configurable Model + Configuration = Configured model
• Question 1:
Is a particular configuration correct?
• Question 2:
Is there a correct configuration?
• Question 3:
How to characterize the set of all correct configurations?
• Question 4:
How to auto-complete a configuration?
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7. Transition Flow
Place XOR-split
Can t3 be blocked? AND-split
AND-join
XOR-join
Token
pI
pI
t1 t2
t1 t2
p2 p3 p4 p2 p3 p4
t5 t6 t5 t6
t3 t4 t4
p6 p6
p5 t8 p5 t8
p7 p7
t7 t7
pO pO
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8. Transition Flow
Place XOR-split
Block t1 and hide t3 ? AND-split
AND-join
XOR-join
Token
p1 p1
Prepare Prepare Prepare
Travel Form t1 t2 Travel Form
t2 Travel Form
(Secretary) (Employee) (Employee
p2 p2
Arrange
p3 t3 travel p4 p3 τ p4
insurance t3
(Employee)
p5 p5
Request for Check & Update
t7 t4 Travel Form t5 τ Request for Check & Update
change
(Admin) (Employee) change t7 t4 Travel Form t5 τ
(Admin) (Employee)
p6
p6
Submit
Travel Form Submit
t6 Travel Form
for Approval t6 for Approval
(Employee)
(Employee)
p7
p7
Approve Reject
Travel Form t8 Travel Form t9 Approve Reject
(Admin) (Admin) Travel Form t8 Travel Form t9
(Admin) (Admin)
p8
p8
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9. Transition Flow
Place XOR-split
Block t4 also? AND-split
AND-join
XOR-join
Token
p1 p1
Prepare Prepare Prepare
Travel Form t1 t2 Travel Form t2 Travel F
(Secretary) (Employee) (Emplo
p2 p2
Arrange
p3 t3 travel p4 p3 t3 τ p4
insurance
(Employee)
p5 p5
Request for Check & Update Request for
change t7 t4 Travel Form t5 τ change t7 t5 τ
(Admin) (Employee) (Admin)
p6 p6
Submit Submit
Travel Form Travel Form
t6 for Approval
t6 for Approval
(Employee) (Employee)
p7 p7
Approve Reject Approve Reject
Travel Form t8 Travel Form t9 Travel Form t8 Travel Form t9
(Admin) (Admin) (Admin) (Admin)
p8 p8
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10. Existing approaches
• Most approaches only consider the
syntactical issues or simply create the
configured model and analyze it (i.e.,
trail and error).
• Our earlier approach using a SAT
solver is an exception to this rule, but
is limited to free-choice WF-nets.
W.M.P. van der Aalst, M. Dumas, F. Gottschalk, A.H.M. ter Hofstede, M. La Rosa, J.
Mendling, Preserving Correctness During Business Process Model Configuration. In
Formal Aspects of Computing (FACS). Vol. 22 No. 3-4, 2010.
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11. New approach
• Based on partner synthesis developed in the
Rostock group.
• Implemented in C-YAWL using Wendy.
• Advantages:
1. No syntactical restrictions (i.e. beyond WF-nets
and free-choice).
2. Complete characterization of all correct
configurations at design time: the so-called
configuration guideline.
3. Computation time is moved from configuration
time to design time. PAGE 10

12. Open nets and weak termination
Open net:
• Labeled Petri net without any
syntactical restrictions.
• Special label: τ
• Set of final markings, in this case
[p4].
Correctness notion:
• weak termination: it is always
possible to reach a final marking
(weaker than classical soundness)
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13. Composition of open nets
p11 p21 p11 p21
y t11 t12 x t21 x τ (t12,
t21)
p12 p12
p22 p22
τ t13 t14 z
= τ t13 τ (t14,
t22)
p13 t22 z p13
t15 z τ (t15,
t22)
p14 p23 p14 p23
Ω ={[p14]} Ω ={[p23]} Ω ={[p14,p23]}
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14. Controllability
• An open net is controllable if there exists another
open net such that their composition is weakly
terminating.
• An open net is called a partner of another open net if
their composition is weakly terminating.
• A controllable open net has at least one partner.
• There are efficient techniques to check controllability
and to synthesize partners.
[Karsten Wolf. Does My Service Have Partners?. T. Petri Nets and Other Models
of Concurrency 2: 152-171 (2009)]
• These are implemented in Wendy.
[Niels Lohmann, Daniela Weinberg. Wendy: A Tool to Synthesize Partners for
Services. Petri Nets 2010: 297-307.]
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15. Controllability
p11
y t11 t12 x
weakly
p14 p12
= terminating
τ t13 t14 z partner??
p13
Ω ={[p13]}
Idea:
good configuration = partner!
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16. Configurable interface (allow by default)
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17. Configurable interface (block by default)
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18. Configuration guideline (allow by default)
CG
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19. Configurable interface (block by default)
CG PAGE 18

20. Configuration guideline (allow by default)
CG
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21. Configuration guideline (allow by default)
CG
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22. Configuration guideline (allow by default)
CG
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23. Configuration guideline (allow by default)
CG
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24. Tool support
• YAWL editor
− Creating C-YAWL models
− Configuring C-YAWL models
− Verification and auto-completion (using SAT solver
and/or Wendy)
• YAWL engine Configuration
model (.cml)
• YAWL services Quaestio
C-YAWL Editor
C-YAWL model
(.yawl)
Configured YAWL Engine
C-YAWL (.yawl) spec. (.yawl)
Questionnaire Mapping
Model (.qml) (.cmap)
Process
Mapper Process
Configured Individualizer EPC
Configurator C-EPC (.epml) (.epml)
C-EPC model
(.epml)
Questionnaire
Designer
C-EPC Designer Process Merger
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25. C-YAWL
p1
Prepare Prepare
Travel Form t1 t2 Travel Form
(Secretary) (Employee)
p2
Arrange
p3 t3 travel p4
insurance
(Employee)
p5
Request for Check & Update
change t7 t4 Travel Form t5 τ
(Admin) (Employee)
p6
Submit
Travel Form
t6 for Approval
(Employee)
p7
Approve Reject
Travel Form t8 Travel Form t9
(Admin) (Admin)
p8
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26. C-YAWL
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27. Conclusion
• New approach for ensuring the correctness of process
configurations based on partner synthesis.
• Advantages:
1. No syntactical restrictions (i.e. beyond WF-nets and free-
choice).
2. Complete characterization of all correct configurations at
design time: the so-called configuration guideline.
3. Computation time is moved from configuration time to
design time.
• Implemented in C-YAWL using Wendy.
− Complete support for workflow configuration,
verification, and enactment.
− Autocomplete, domain knowledge, etc.
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28. More information
• www.processconfiguration.com
(various references to configuration literature and a comprehensive toolset)
• www.yawlfoundation.org
(YAWL has been extended to support configuration, cf. C-YAWL)
• service-technology.org
(paper and tools - including Wendy - related to the analysis of services)
• www.win.tue.nl/coselog
(webpage of the CoSeLoG project)
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