Recently, we came across a requirement of exposing the BPEL service to be accessible over HTTP without exposing it as SOAP service. We have used the HTTP binding for this purpose. This blog provides the useful information on coming up with actual HTTP url to be used for testing as we faced issues with testing the process from EM console.
Basically the url should be some thing like below for GET invocation:
<<url given in EM>>/?<your query string>&operationName=<get operation name>
Just wanted to add simple update on this topic, the URL is working even by giving different name for operation other than default operation name ‘Request-Response’. The same has been tested from SOAP UI (GET method invocation).
Siva's Blog 