call multiple flow services in parallel and consolidate results at end

could you suggest which is the best way to call multiple flow services(which will invoke individual DB queries) in parallel(asynchronous) within a main flow service and consolidate all responses and send as one from main flow service.
JMS or Publish or Java.doInvoke()?

Try this
http://tech.forums.softwareag.com/techjforum/posts/preList/69644/238300.page#238300