Hi meeta Nair,
Failing in the sense you are getting an error message?
What is happening. If there was a Dump in the Job, Check in ST22 for analysis
If the is some other error and you dont have job log. Then Keep a Wait statement for 5Seconds in the program.
Then open SM37 and go to the Application Server-> then gor Processes (Screw Symbol) then select your program process. From the Menu program select Debug Program. This is one way to debug a Background Job and other ways already mentioned by others..
Hope this Helps. 