The document discusses structural abstraction in business process diagrams, particularly focusing on preserving process logic while omitting insignificant details. It outlines operations like elimination and aggregation, defines auxiliary process models, and establishes various relationships between process fragments. The conclusion highlights a proposed approach to manage BPMN 1.2 process models effectively.

1. Structural Aspects of Business Process Diagram Abstraction Sergey Smirnov [email_address] BPMN 2009 20 July 2009

2. Motivation 62 activities 23 events 11 gateways 96 nodes

3. Existing Approaches AOK & BPT Project Notation: simplistic notation EPC Eshius & Grefen Notation: UML activity diagram Proviado Project Notation: simplistic Liu and Shen Notation: simplistic notation

4. Business Process Model Abstraction … is generalization of a process model preserving the overall process logic and leaving out insignificant process details in order to retain information relevant for a particular purpose.

5. Abstraction Operations Elimination Aggregation

6. Abstraction of Activities

7. Stepwise Abstraction 1 2

8. Do’s and Dont’s Do’s preserve ordering constraints abstract sound process models address rich semantics of BPMN Dont’s address process model business semantics

9. Auxiliary Business Process Model (N, E, type) is an auxiliary business process model, where: is a set of nodes, where N A ≠ Ø – a set of activities; N G – a set of gateways; the sets are disjoint is a set of directed edges between nodes representing control flow is a connected graph every activity has at most 1 incoming & at most 1 outgoing edge there is at least 1 activity with no incoming edges (start activity) and at least 1 activity with no outgoing edges (end activity) assigns a control flow construct to a gateway every gateway is either a split or a join; splits have exactly 1 incoming edge and at least 2 outgoing; joins have at least 2 incoming edges and exactly 1 outgoing.

10. Single Entry Single Exit Fragment SESE fragment is a fragment which has exactly: 1 incoming edge – 1 outgoing edge

11. Canonical SESE Fragment canonical SESE fragments

12. Canonical SESE Fragment non-canonical SESE fragments

13. Relations between SESE Fragments p arent - child predecessor-successor if the node set of SESE fragment f 1 is the subset of node set of SESE fragment f 2 , then f 1 is the child of f 2 and f 2 is the parent of f 1 SESE fragment f 1 precedes SESE fragment f 2 (and f 2 succeeds f 1 ) if the outgoing edge of f 1 is the incoming edge of f 2 P 1 c 2 c 1 p 1 s 2 s 1 p 2

14. Auxiliary Concepts A – an activity to be abstracted sese A – canonical SESE fragment containing A sese min – a minimal canonical SESE fragment containing A and at least one more activity ( sese min ≠ sese A ); there are 2 options for sese min : there is canonical SESE fragment sese A’ which is in predecessor-successor relation with sese A ; then sese min is a SESE fragment with the incoming edge of the predecessor and the outgoing edge of the successor if 1 does not hold, than sese min is a SESE fragment which is the parent of sese A

15. Variety of BPMN Elements 6 Gateway types 29 Event types 6 activity types 3 types of sequence flow Message flow Associations …

16. Connecting Objects message flow associations sequence flow normal flow exception flow

17. Message Flow message flow ≠ control flow

18. Sequence Flow normal flow = exception flow = control flow

19. Associations associations ≠ control flow

20. Activity Allocation Types compensation activity within ad-hoc subprocess within sequence flow

21. Abstraction of an Activity in a BPD abstractBPD ( BPD diagram, Activity activity) if activity is compensation activity then eliminate activity, corresponding compensation event, and association return if activity in adHocSubprocess then collapse adHocSubprocess return find sequence flow flow where activity is allocated construct auxiliary model auxiliaryModel for flow perform abstraction in auxiliaryModel make necessary updates in diagram

22. BPD to Auxiliary Model Mapping Normalization Preliminary flow construction Auxiliary model construction

23. Normalization (I)

24. Normalization (II)

25. Normalization (III)

26. Normalization (IV)

27. Normalization (V)

28. Preliminary Flow Construction BPMN Preliminary Flow

29. Preliminary Model to Auxiliary Model Preliminary flow Auxiliary Notation activities gateways preliminary flow 1 2 3

30. Functions ref in and ref out BPMN Auxiliary Notation ref in : N -> P(A) ref out : N -> P(A) in out A – the set of edges in a BPD

31. BPMN Auxiliary Notation

32. BPD Update: Events usually events are concealed within an identified SESE fragment multiple start/end events signal events

33. BPD Update: Message Flow

34. BPD Update: Data encapsulation of data

35. Example: Initial Model

36. Example: Abstracted Model

37. Alternatives: Ad-hoc Subprocesses

38. Alternatives: Message Flow

39. Challenges: Groups ? ?

40. Challenges: End Events in general case requires human intervention Aggregation may lead to: deadlocks missing throwing cancel events missing throwing error events

41. Conclusions We proposed the structural abstraction approach which is: capable of handling BPMN 1.2 process models order preserving capable of handling graph-structured process models