A Case Study of Web Services Orchestration

  • Manuel Mazzara
  • Sergio Govoni
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3454)


Recently the term Web Services Orchestration has been introduced to address composition and coordination of Web Services. Several languages to describe orchestration for business processes have been presented and many of them use concepts such as long-running transactions and compensations to cope with error handling. WS-BPEL is currently the best suited in this field. However, its complexity hinders rigorous treatment. In this paper we address the notion of orchestration from a formal point of view, with particular attention to transactions and compensations. In particular, we discuss web π  ∞  an untimed subcalculus of web π [15] which is a simple and conservative extension of the π-calculus. We introduce it as a theoretical and foundational model for Web Services coordination. We simplify some semantical and pragmatical aspects, in particular regarding temporization, gaining a better understanding of the fundamental issues. To discuss the usefulness of the language we consider a case study: we formalize an e-commerce transactional scenario drawing on a case presented in our previous work [12].


Customer Preference Purchase Order Purchase Transaction Purchase Request Fusion Calculus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Andrews, T., Curbera, F., et al.: Web Service Business Process Execution Language, Working Draft, Version 2.0, December 1 (2004)Google Scholar
  2. 2.
    Berger, M.: Basic Theory of Reduction Congruence for Two Timed Asynchronous π-calculi. In: Gardner, P., Yoshida, N. (eds.) CONCUR 2004. LNCS, vol. 3170, pp. 115–130. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  3. 3.
    Berger, M.: Towards Abstractions for Distributed Systems. PhD Thesis, Imperial College, London (2002)Google Scholar
  4. 4.
    Berger, M., Honda, K.: The Two-Phase Commit Protocol in an Extended π-Calculus. In: EXPRESS 2000: Proceedings of the 7th International Workshop on Expressiveness in Concurrency, ENTCS, vol. 39(1). Elsevier, Amsterdam (2000)Google Scholar
  5. 5.
    Microsoft BizTalk Server, Microsoft Corporation,
  6. 6.
    Bruni, R., Laneve, C., Montanari, U.: Orchestrating Transactions in Join Calculus. In: Brim, L., Jančar, P., Křetínský, M., Kucera, A. (eds.) CONCUR 2002. LNCS, vol. 2421, pp. 321–337. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  7. 7.
    Bruni, R., Melgratti, H., Montanari, U.: Theoretical Foundations for Compensations in Flow Composition Languages. In: To appear in POPL 2005 (2005)Google Scholar
  8. 8.
    Bocchi, L., Laneve, C., Zavattaro, G.: A Calculus for Long-running Transactions. In: Najm, E., Nestmann, U., Stevens, P. (eds.) FMOODS 2003. LNCS, vol. 2884, pp. 124–138. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  9. 9.
    Butler, M., Ferreira, C.: An Operational Semantics for StAC, a Language for Modelling Long-running Business Transactions. In: De Nicola, R., Ferrari, G.-L., Meredith, G. (eds.) COORDINATION 2004. LNCS, vol. 2949, pp. 87–104. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  10. 10.
    Chessel, M., Vines, D., Griffin, C., Green, V., Warr, K.: Business Process Beans: System Design and Architecture Document. Technical report.IBM UK Laboratories (January 2001)Google Scholar
  11. 11.
    Christensen, E., Curbera, F., Meredith, G., Weerawarana, S.: Web Services Description Language (WSDL 1.1), W3C, Note 15 (2001),
  12. 12.
    Guidi, C., Lucchi, R., Mazzara, M.: A Formal Framework for Web Services Coordination. In: 3rd International Workshop on Foundations of Coordination Languages and Software Architectures, London (2004)Google Scholar
  13. 13.
    Hoare, T.: Long-Running Transactions. Powerpoint presentation,
  14. 14.
    Kavantzas, N., Olsson, G., Mischkinsky, J., Chapman, M.: Web Services Choreography Description Languages,
  15. 15.
    Laneve, C., Zavattaro, G.: Foundations of Web Transactions. In: Sassone, V. (ed.) FOSSACS 2005. LNCS, vol. 3441, pp. 282–298. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  16. 16.
    Leymann, F.: Web Services Flow Language (WSFL 1.0), Member IBM Academy of Technology, IBM Software Group (2001),
  17. 17.
    Little, M.: Web Services Transactions: Past, Present and Future,
  18. 18.
    Mazzara, M., Lucchi, R.: A Framework for Generic Error Handling in Business Processes. In: First International Workshop on Web Services and Formal Methods (WS-FM). Pisa (2004)Google Scholar
  19. 19.
    Milner, R.: Function as Processes. Mathematical Structures in Computer Science 2(2), 119–141 (1992)MathSciNetCrossRefzbMATHGoogle Scholar
  20. 20.
    Milner, R.: Communicating and Mobile Systems: the π-Calculus. Cambridge University Press, Cambridge (1999)zbMATHGoogle Scholar
  21. 21.
    Milner, R., Parrow, J., Walker, D.: A calculus of mobile processes. Journal of Information and Computation 100, 1–77 (1992)MathSciNetCrossRefzbMATHGoogle Scholar
  22. 22.
    Parrow, J., Victor, B.: The Fusion Calculus: Expressiveness and Symmetry in Mobile Processes. In: LICS 1998: Proceedings of the 13th Symposium on Logic in Computer Science. IEEE Computer Society Press, Los Alamitos (1998)Google Scholar
  23. 23.
    Peltz, C.: Web Services Orchestration and Choreography. IEEE Computer 36(10), 46–52 (2003)CrossRefGoogle Scholar
  24. 24.
    Sangiorgi, D., Walker, D.: The π-calculus: a Theory of Mobile Processes. Cambridge University Press, Cambridge (2001)zbMATHGoogle Scholar
  25. 25.
    Thatte, S.: XLANG: Web Services for Business Process Design, Microsoft Corporation (2001),
  26. 26.
    Universal Description, Discovery and Integration for Web Services (UDDI) V3 Specification,
  27. 27.
    van der Aalst, W.M.P.: Pi calculus versus Petri nets: Let us eat “humble pie” rather than further inflate the ”Pi hype”
  28. 28.
    Workflow Management Coalition,
  29. 29.
  30. 30.
  31. 31.
    Weikum, B., Vossen, G.: Transactional Information Systems. Morgan Kaufmann, San Francisco (2002)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Manuel Mazzara
    • 1
  • Sergio Govoni
    • 2
  1. 1.Department of Computer ScienceUniversity of BolognaItaly
  2. 2.Imaging Science and Information Systems CenterGeorgetown UniversityWashington, DCUSA

Personalised recommendations