1. a university for the world real R © 2009, www.yawlfoundation.org Chapter 14 EPCs Jan Mendling

2. a university for the world real R 2 © 2009, www.yawlfoundation.org Agenda Introduction to EPCs Mapping EPCs to YAWL Mapping YAWL to EPCs Transformation based on Reachabilty Graph

3. a university for the world real R 3 © 2009, www.yawlfoundation.org EPC Background Event-Driven Process Chains (EPCs) have been invented in joint research project by IWi Saarbrücken and SAP in the early 1990s EPCs are part of the ARIS (Architecture of Integrated Information Systems) methodology defined by Scheer They are promoted by respective ARIS modeling tool family distributed by IDS Scheer AG EPCs are used in many large scale industry projects where the ARIS software of IDS Scheer is used EPCs are used a.o. as the language of the SAP Reference Model

4. a university for the world real R 4 © 2009, www.yawlfoundation.org Introduction to EPCs Functions Events Connectors (and,xor,or) Control flow arcs

5. a university for the world real R 5 © 2009, www.yawlfoundation.org EPC Semantics: Transition Relation Cuntz, Kindler, 2004 5

6. a university for the world real R 6 © 2009, www.yawlfoundation.org EPC Semantics: Transition Relation II Non-local semantics 6

7. a university for the world real R 7 © 2009, www.yawlfoundation.org Workflow Pattern Support

8. a university for the world real R 8 © 2009, www.yawlfoundation.org Mapping EPCs to YAWL Challenges State representation There is no direct counterpart for YAWL conditions in EPCs Connector chains There can be several connectors in a row while in YAWL splits and joins are part of tasks Multiple start and end events EPCs can have multiple start and end events while YAWL requires one unique start and one unique end

9. a university for the world real R 9 © 2009, www.yawlfoundation.org Mapping EPCs to YAWL

10. a university for the world real R 10 © 2009, www.yawlfoundation.org Mapping EPCs to YAWL (Cont.)

11. a university for the world real R 11 © 2009, www.yawlfoundation.org Mapping YAWL to EPCs Challenges Free choice property EPCs are free choice while YAWL can have non-free choice behavior Multiple instantiation YAWL offers multiple instantiation, EPCs do not Cancellation YAWL offers cancellation, EPCs do not Syntax In EPCs functions and events have to alternate

12. a university for the world real R 12 © 2009, www.yawlfoundation.org Mapping YAWL to EPCs

13. a university for the world real R 13 © 2009, www.yawlfoundation.org Mapping YAWL to EPCs

14. a university for the world real R 14 © 2009, www.yawlfoundation.org Non-free choice behavior non-free choice

15. a university for the world real R 15 © 2009, www.yawlfoundation.org A corresponding EPC free choice

16. a university for the world real R 16 © 2009, www.yawlfoundation.org Different YAWL, same EPC

17. a university for the world real R 17 © 2009, www.yawlfoundation.org A YAWL condition and two EPC connectors

18. a university for the world real R 18 © 2009, www.yawlfoundation.org Transformation using synthesis Take YAWL Calculate Reachability Graph Synthesize EPC Take EPC Calculate Reachability Graph Synthesize YAWL

19. a university for the world real R 19 © 2009, www.yawlfoundation.org Reachability Graph

20. a university for the world real R 20 © 2009, www.yawlfoundation.org Summary EPCs are heavily used in industry practice A mapping to YAWL is rather straight-forward A mapping from YAWL to EPCs is challenging due to missing non-free-choice, cancellation and multiple instance support A behavior-preserving transformation is possible using the reachability graph and synthesis techniques.