1. Business Process Modeling with Event-driven Process Chains
Jan Mendling
Institute of Information Systems and New Media
WU Wien

2. You will learn in this session…
What business process management is,
How business process modeling works, and
What event-driven process chains are.

3. 1. Business Process Management
BPM and Workflow
1. Business Process Management

4. A Retail Process Welcome customer Offer Clothes Bill Clothes
Hand over clothes

5. Different business processes
Production process
Support process
Managerial process

6. What is a Business Process?
Organization Chart: units with assigned tasks
Business Process: execution of tasks coordination between tasks
Activity: elementary part of a working step
Organization Chart WU Wien

7. Definitions related to Business Process
“A process is a completely closed, timely and logical sequence of activities which are required to work on a business object” (e.g. invoice).
“A business process is a special process that is directed by the business objectives of a company and by its business environment.” (Becker, Kahn 2003).
“The real structure of the operation is that of a river. It continuously creates and distributes new products and services based on the same tasks or on tasks which only vary in detail.” (Nordsieck 1972).
“The truth of Being and Nothing is accordingly the unity of the two: and this unity is BECOMING” (Hegel: Phänomenologie des Geistes, 1807)
“Panta rhei - Everything flows, nothing stands still.” (Heraklitus of Ephesos, BC)

8. Business Process versus Case
Activity
Business Process Attributes
Case (Process Instance)
Instance Activity
Case Attributes
Car Assembly Process
Mount doors
Car body number, (Buyer), Car color
Car Assembly Case 3324
Mount doors on 3324
Car body number 3324, Buyer Henry Ford, Car color white

9. Business Process Management
Task efficiency “It follows that the most important object of both the workmen and the management should be the training and development of each individual in the establishment, so that he can do (at his fastest pace and with the maximum of efficiency) the highest class of work for which his natural abilities fit him.” (Frederick W. Taylor 1911)
Coordination efficiency “The question in view of this overall thinking is how to divide the tasks of a company other than by natural technical process phases?” (Nordsieck 1972)

10. BPM Lifecycle
v.d.Aalst, t.Hofstede, Weske 2003

11. 2. Business Process Modeling
BPM and Workflow
2. Business Process Modeling

12. Why Modeling?

13. What is Modeling?
“A model is a simplifying mapping of reality to serve a specific purpose” (Stachowiak: Allgemeine Modelltheorie, 1973)
Mapping: representation of natural or artificial originals that can be models themselves
Simplying: only those attributes of the original that are considered relevant (abstraction)
Pragmatics: model is used by modeler in place of original for a certain time and a certain purpose

14. Guidelines of Modeling (GoM)
Correctness: relates to the mapping, capture attributes of the original correctly
Relevance: abstract from those aspects that are not relevant
Economic Efficiency: Keep an eye on the purpose of modeling task
Clarity: the model should be intuitive to understand for involved stakeholders
Comparability: Use a similar mapping for similar aspects
Systematic Design: define interfaces to related models
Schütte, Rotthowe: The Guidelines of Modeling - An Approach to Enhance the Quality in Information Models, 1998.

15. Purposes of Business Process Modeling: Organization Design
Process Documentation
Process Reorganization
Process Monitoring and Controlling
Continuous Improvement
Quality Management: ISO 9000
Benchmarking: Compare with best practice
Knowledge Management:

16. Purposes of Business Process Modeling: Information Systems Design
Selection of ERP software
Model based Customizing
Software Development
Workflow Management
Simulation

17. What to model of a business process
Tasks
Coordination between tasks
synchronization
decisions
parallel work
repetition …
Organizational responsibilities
Required resources
Information input and output

18. Modeling method, technique, and language
Karagiannis, Kühn 2002: Metamodelling Platforms.

19. Business Process Modeling Languages
Event-driven Process Chains (EPC)
Petri Nets
Business Process Modeling Notation (BPMN)
UML Activity Diagrams

20. Business Process Modelling Tools 2004
Gartner: Magic Quadrant for Business Process Analysis, 2004, 04 March 2004 (

21. The BPM Life cycle

22. 3. Event-driven Process Chains (EPC)
BPM and Workflow
3. Event-driven Process Chains (EPC)

23. Example from the SAP Reference Model

24. EPC Semantics: prose version
Functions: activities of the business process
Events: pre- and post-conditions of functions
AND split: activates all subsequent branches in concurrency
OR split: triggers one, two or up to all of multiple subsequent branches.
XOR split: defines a choice to activate one of multiple subsequent branches.
AND join: waits for all incoming branches to complete.
OR join: waits for all active branches to complete.
XOR join: continue when one of alternative branches has completed.
AND
Split
Join
XOR
EPC
Function
Event
Activity
Pre -
&
Post
condition OR

25. Exercise
Have a look at the EPC business process model below. Write down the information that is represented by this model in English language sentences. Be precise and detailed, but not dissipated. Use this little exercise for a brief explanation in how far modeling is efficient.

26. Exercise
Wenn der Filialbestand unter die Bestellmenge fällt, wird automatisch eine Bestellung generiert. Diese wird gegen den Zentralbestand geprüft. Falls dieser nicht ausreicht, werden Artikel nachbestellt. Wenn diese eingetroffen sind oder falls der Bestand von vornherein ausreicht, werden die Artikel ausgeliefert. Somit ist die Bestellung abgeschlossen.

27. Solution

28. Combine Views with extended EPCs (eEPC)

29. Exercise
Die automatische Bestellgenerierung erfolgt auf Seiten der Filiale. Die erzeugte Bestellung geht in das Warenwirtschafts- system ein, anhand dessen die Zentrale Disposition den Zentralbestand prüft. Die Zentrale Disposition führt auch eine eventuelle Nachbestellung aus, die zu einer Bereitstellung der Waren führt. Der Transport ist für die Auslieferung der Waren zuständig, die ebenfalls im Warenwirtschaftssystem erfasst wird.

30. Solution

31. BPM and Workflow
4. Semantic Issues

32. EPC Semantics: Transition Relation
Cuntz, Kindler, 2004

33. EPC Semantics: Transition Relation II
Non-local semantics

34. How EPCs work

35. How EPCs work II

36. How EPCs work III
Only if nothing can be propagated to arc a21, c1 is allowed to proceed.
But if c1 is allowed to proceed, a folder can be propated to a21.
But if something can be propagated to a21, c1 may not proceed.
If c1 may not proceed, nothing can be propagated to arc a21 (see 1.) …

37. Which one can fire?

38. Exercise
Bei einer Ausschreibung werden zuerst die verschiedenen Einreichungen geprüft. Falls kein Angebot den Erwartungen entspricht, wird geprüft, ob die Ausschreibung zurückgestellt werden kann. Falls nein erfolgt eine neue Ausschreibung. Falls ja wird die Ausschreibung auf Wiedervorlage gestellt. Falls mindestens ein Angebot den Erwartungen entspricht, wird das beste Angebot ausgewählt. Wenn sowohl das Angebot ausgewählt ist als auch die Ausschreibung auf Wiedervorlage gelegt wurde, wird ein Abschlussbericht erstellt.

39. Solution

40. Problems with Connector Mismatch

41. Problems with Connector Mismatch

42. Lessons Learned
Use structured blocks
Use simple loops

43. BPM and Workflow
5. EPC Reference Models

44. Real World EPC Process Models
SAP Reference Model Keller & Teufel: SAP R/3 Process-oriented Implementation, 1998.
Handels-H-Modell Becker & Schütte: Handelsinformationssysteme, 2nd Edition, 2006.
Y-CIM-Modell für die Produktion Scheer: Wirtschaftsinformatik – Referenzmodelle für industrielle Geschäftsprozesse, 7th Edition, 1997.
ARIS Platform 7.0 by IDS Scheer AG:

45. The SAP Reference Model
About 10,000 information models
5 Hierarchy Levels
29 Branches
Various model types: data, organization, processes, etc.
604 EPC business process models

46. Reusing Reference Models
Change EPC Models
Change SAP System

47. Why Correct EPC Models? Misunderstandings in Teaching Processes
Comparing System with existing processes
Customization of System

48. How to find errors? Soundness (v.d.Aalst 1997):
For every state that is reachable from the start, the end can be reached.
If the end is reached, there is no activity still active.
All activities can be reached.
Relaxed Soundness (Dehnert, Rittgens 2001):
Every activity participates in a run from start to end.

49. Verification Approach

50. An EPC from the SAP Reference Model

51. Mapping to YAWL

52. The resulting YAWL net

53. Petri Net analysis within WofYAWL

54. Potential Correction

55. Results

56. Modeling Error 1: Deadlock

57. Modeling Error 2: Livelock

58. Modeling Error 3: Multiple Instantiation

59. Why Errors Hypotheses: Model Size Model Complexity Error Patterns
Independent variables:
Number of each element type
Cycles
Complexity metrics based on state space
Logistic Regression:
Explain error (yes/no)
Nagelkerke R2: and 0.26 in significant models
Correct Classification: about 95%

60. Conclusion Correctness is an issue in practice
Relaxed Soundness as a lower bound
At 5.6% of the models with errors
Model Complexity matters
Closer coupling of process models and enterprise system needed

61. BPM and Workflow
6. Summary

62. ARIS House of Business Engineering
Nüttgens, Scheer 2000

63. Lessons Learned
Use structured blocks
Use simple loops