This document discusses modeling service choreographies and the challenges of asynchronous communication. It introduces the concept of desynchronizability checking to detect errors that can occur when a choreography assumes synchronous communication but the underlying services communicate asynchronously. Several resolution strategies are presented to address errors detected by desynchronizability checking, including precedence agreements, individual decisions, and negotiation of outcomes upon conflicting messages. The challenges of asynchronous communication must be considered when modeling choreographies.

1. Non-desynchronizable Service Choreographies Gero Decker 1 , Alistair Barros 2 , Frank Michael Kraft 3 , Niels Lohmann 4 1 Hasso-Plattner-Institute, Potsdam, Germany 2 SAP Research, Brisbane, Australia 3 SAP AG, Walldorf, Germany 4 University of Rostock, Germany

4. Modeling Choreographies Interconnection Modeling

5. Modeling Choreographies Interconnection Modeling incompatible loops definition of process instantiation incompatible branching structures incompatible sequence flow abstraction level = messages

6. Modeling Choreographies Interaction Modeling atomic interactions decision ownership global control flow dependencies complex interactions global loops process instantiation unspecified

8. Modeling Choreographies

9. Modeling Choreographies Does this choreography make sense in an asynchronous world?

11. Studying the Desynchronized Net Deadlock