Exploring the connection of choreography and orchestration with exception handling and finalization/compensation

Web service choreography describes protocols for multiparty collaboration, whereas orchestration focuses on single peers. One key requirement of choreography is to support transactions, which makes exceptional handling and finalization very important features in modelling choreography. A projection is a procedure which takes a choreography and generates a set of processes in the orchestration level. Given a choreography, how to project exceptional handling and finalization constructs is still an open problem. This paper aims to study exception handling and transactionality in choreographies from a projection view. We propose formal languages for both choreography and orchestration with trace semantics, and a projection based on the relationship between choreography and scope rooted in WS-CDL and WS-BPEL respectively.