All, I have gone through various blogs and documentation explaining the reasons for choosing a specific component,But,It is always a close call when it comes to making a very important decision as the real time uses case we generally deal with always fall in a border making it difficult to decide. Use case: A legacy system has to communicate with a third party system for sending some job details. For the same it uses an service intermediary. This service intermediary has to a) Receive the message from the legacy system. ( Preferably as EDN event as its easy for the legacy system to through an event) b) Very light orchestration ( in the future) c) Route it to the Mobile enablement application/ system. Generic: d) Need to provide a fault management / handling. e) Authentication / Authorization. Having these requirements, I thought an OSB would be a right component to be used as we are focused on routing in a decoupled way with light orchestration and business agility. However can OSB support a. subscribe to EDN events ? If yes how ? Can it have Oracle Apps adapter to get the events from R12 like BPEL? b. Can it use the same fault management framework written for SOA suite ( policies and bindings) ? On the other hand, I am having thoughts on why not use BPEL process itself. We can turn Auditing to off and will not have any dehydration points in the bpel process thus making it stateless ( just like OSB ?) if that is the major difference we are looking at ? Service virtualization ( dynamically changing the end point ) can also be acheived in bpel. and why not Mediator ? I know everywhere people talk about using mediator for intra composite commmunication but at the same time they suggest using it while writing to file / adapter or call a external service exposed as SOAP WSDL too. Now for our use case, a mediator can listen to events from the legacy system and route it to the target mobile enablement service. ( Note : BPEL and mediator can use fault management , EDN's, Oracle apps adapter and also can be made stateless by turning the audit to off . So if you are still suggesting OSB please back it up with strong reason rather than just theoritcally saying that its a standard to use in case of routing and stateless etc..) Kindly help ! Regards, Sridhar.