Our EDI implementation has been by and large reliable for about two years.  Recently due to a field length change we had to update the field map. That went fine and worked for several weeks. Now in the afternoon the batch job processing the EDI incoming traffic and creating customer orders stalls or hangs without any visible cause.  Killing and restarting the job seems to fix it for a bit but then after a few hours it may stop again.

Any ideas as to the cause or how to monitor and debug this issue? 

I have not been able to find any documents that address things that might go wrong. 

Thanks for any pointers or assistance.