Adaptive web service composition

Web services have played an important role in the development of distributed systems. In particular, the possibility of composing already implemented web services in order to provide a new functionality is an interesting approach for building distributed applications and business processes. The possibility of dynamically composing web services is also apparent. Current approaches address to this point, but they do not adopt established specifications, like WS-BPEL, as they usually propose modifications in the rules of business process specifications by imposing more difficulties to implement the system. This paper proposes a policy-driven approach for enabling web service adaptability through a semantic modification in the invocation primitive of WS-BPEL, whilst mantains its syntax unaffected. Hence, programmers may define dynamic web service compositions without changing the source code. The approach has been applied to a loan approval system in order to illustrate it.