A formal account of WS-BPEL

Alessandro Lapadula, Rosario Pugliese and Francesco Tiezzi

Dipartimento di Sistemi e Informatica, Universita' di Firenze

We introduce Blite, a lightweight language for web services orchestration designed around some of WS-BPEL peculiar features like partner links, process termination, message correlation, long-running business transactions and compensation handlers. Blite formal presentation helps clarifying some ambiguous aspects of the WS-BPEL specification, which have led to engines implementing different semantics and, thus, have undermined portability of WS-BPEL programs over different platforms. We illustrate the main features of Blite by means of many examples, some of which are also exploited to test and compare the behaviour of three of the most known free WS-BPEL engines.