An Alternative Way to Analyze Workflow Graphs
At the CAiSE conference in Heidelberg in 1999, Wasim Sadiq and Maria Orlowska presented an algorithm to verify workflow graphs . The algorithm uses a set of reduction rules to detect structural conflicts. This paper shows that the set of reduction rules presented in  is not complete and proposes an alternative algorithm. The algorithm translates workflow graphs into so-called WF-nets. WF-nets are a class of Petri nets tailored towards workflow analysis. As a result, Petri-net theory and tools can be used to verify workflow graphs. In particular, our workflow verification tool Woflan  can be used to detect design errors. It is shown that the absence of structural conflicts, i.e., deadlocks and lack of synchronization, conforms to soundness of the corresponding WF-net . In contrast to the algorithm presented in , the algorithm presented in this paper is complete. Moreover, the complexity of this alternative algorithm is given.
KeywordsOutput Node Input Node Reduction Rule Input Place Rank Theorem
Unable to display preview. Download preview PDF.
- 3.E. Best. Structure Theory of Petri Nets: the Free Choice Hiatus. In W. Brauer, W. Reisig, and G. Rozenberg, editors, Advances in Petri Nets 1986 Part I: Petri Nets, central models and their properties, volume 254 of Lecture Notes in Computer Science, pages 168–206. Springer-Verlag, Berlin, 1987.CrossRefGoogle Scholar
- 4.F. Casati, F. S. Ceri B. Pernici, and G. Pozzi. Conceptual Modeling of Workflows. In M.P. Papazoglou, editor, Proceedings of the 14th International Object-Oriented and Entity-Relationship Modeling Conference, volume 1021 of Lecture Notes in Computer Science, pages 341–354. Springer-Verlag, Berlin, 1998.CrossRefGoogle Scholar
- 8.M. H. T. Hack. Analysis production schemata by Petri nets. Master’s thesis, Massachusetts Institute of Technology, Cambridge, Mass., 1972.Google Scholar
- 11.E. Kindler and W. M. P. van der Aalst. Liveness, Fairness, and Recurrence. Information Processing Letters, 70(6):269–274, June 1999.Google Scholar
- 12.D. Kuo, M. Lawley, C. Liu, and M. E. Orlowska. A General Model for Nested Transactional Workflows. In Proceedings of the International Workshop on Advanced Transaction Models and Architecture (ATMA’ 96), pages 18–35, Bombay, India, 1996.Google Scholar
- 13.P. Lawrence, editor. Workflow Handbook 1997, Workflow Management Coalition. John Wiley and Sons, New York, 1997.Google Scholar
- 14.H. Lin, Z. Zhao, H. Li, and Z. Chen. A Novel Graph Reduction Algorithm to Identify Structural Conflicts. In Proceedings of the Thirty-Fourth Annual Hawaii International Conference on System Science (HICSS-35). IEEE Computer Society Press, 2002.Google Scholar
- 15.T. Murata. Petri Nets: Properties, Analysis and Applications. Proceedings of the IEEE, 77(4):541–580, April 1989.Google Scholar
- 18.W. Sadiq and M. E. Orlowska. On Correctness Issues in Conceptual Modeling of Workflows. In Proceedings of the 5th European Conference on Information Systems (ECIS’ 97), pages 19–21, Cork, Ireland, 1997.Google Scholar
- 19.W. Sadiq and M. E. Orlowska. Applying Graph Reduction Techniques for Identifying Structural Conflicts in Process Models. In M. Jarke and A. Oberweis, editors, Proceedings of the 11th International Conference on Advanced Information Systems Engineering (CAiSE’ 99), volume 1626 of Lecture Notes in Computer Science, pages 195–209. Springer-Verlag, Berlin, 1999.CrossRefGoogle Scholar