Hi, Of cource all the successful projects need to have their own unit testing done , before one can release the system for integration testing and for user acceptance.
For WBIMB related projects, since the unit is the message broker, we will have to test message flow funcatinality.
What is needed is to simluate the input messages that actually come from the interacting applications (front end or back end).
In order to do this we generally use rfhutil.exe a very good tool which reads the test messages from a file and puts it into a message queue. You can also browse the response messages from any queue, also reply back etc.
This rfhutil can be used to simulate many messages to a fair degree to interact with the WBIMB.
You can download this from this IBM site

Hope this helps..