1. Behavioral Comparison of Process Models Based on Canonically Reduced Event Structures Abel Armas-Cervantes Paolo Baldan Marlon Dumas Luciano García-Bañuelos BPM 2014 1

2. Spot the difference! BPM 2014 2 Not structural differences

3. Spot the difference! BPM 2014 3 Mismatching binary behavioral relations. E.g., behavioral profiles, but do not correspond to any well-accepted notions of equivalence Use process algebra for expressing differences E.g., a(ctt ∧ btt) It is possible to execute task Monitor delivery right after Handle bank transfer in model 1 but not in model 2.

4. Desiderata Diagnostics: Differences explained with intuitive statements Semantics: Well-accepted notion of equivalence – Our choice: Configuration equivalence (True-concurrency spectrum) BPM 2014 4

5. Approach Event structures (ES) as the behavioral representations – Events: occurrences of actions – Relations over the events: behavior dependencies observed between pairs of events BPM 2014 5 Comparator ES1ES2 Model1 Petri net1 Branching process1 Model2 Petri net2 Branching process2

6. Prime vs. Asymmetric event structures BPM 2014 6 Prime Event Structure (PES)Asymmetric Event Structure (AES) Reduction* *Reduction of event structures under hp-bisimulation http://arxiv.org/abs/1403.7181.

7. Canonical reduction Fist contribution: Deterministic order defining a canonical representation Elements: – Lexicographical order of event labels – Order based on the size of the set of events to be merged – Alas... not enough! BPM 2014 7 12 Not canonical

8. Canonical graph label Compute the adjacency matrix of the graph and all its possible permutations Select the largest lexicographical exemplar of the string representation of the permutations – Nauty, a tool to compute canonical graph labeling BPM 2014 8 abc a010 b001 c000 010100000 … bca b010 c000 a100 010000001

9. Deterministic folding Compute combinable set of events Folding order 1.Lexicographic order on the event’s label 2.Size of the set of events to merge 3.Lexicographic order w.r.t. the canonical labels BPM 2014 9

10. What is the catch? Processes with repetitive behavior would require an infinite amount of events Unfoldings of Petri nets BPM 2014 10 Comparator AES1 AES2 Model1 Petri net1 Branching process1 Canonical reduction Model2 Petri net2 Branching process2 Canonical reduction

11. Complete prefix unfolding BPM 2014 11

12. Complete prefix unfolding (1) Truncating techniques based on markings – McMillan and Esparza et al They do not capture all possible causal dependencies BPM 2014 12

13. Our unfolding BPM 2014 13 Capture causal dependencies – We can distinguish repetitive behavior from non-repetitive

14. Current limitations Silent transitions can lead to different prefix unfoldings, even though the processes are equivalent BPM 2014 14

15. Comparator BPM 2014 15 Comparator AES2AES1 Finite representation Canonical Reduction Finite representation Canonical Reduction

16. BP-Diff behavioral process model comparator BPM 2014 16 http://diffbp-bpdiff.rhcloud.com/

17. Summary Technique for a behavioral comparison of process models using AES – Canonical folding of AES – Finite representation using Petri net unfoldings Characterization of cyclic behavior according to task repetitions – Propose a comparison technique of AES BPM 2014 17

18. BPM 2014 18