Assuming that you are using sequences and you are catching errors, use pub.flow:getLastError
In the errors record, there are several variables. One is the actual webMethods service that threw the error. In the catch sequence, I create and set a variable that contains my flow name, since it will not necessarily show up. Also, remember that if you call a child flow that does not contain the sequence setup for try/catch, it will throw to the calling parent error trap.
Hope this helps.
Ray
#Flow-and-Java-services#Integration-Server-and-ESB#webMethods