background job failed because of authorization

We have a job which runs OK in foreground but when defined in background.
It failed and the log said it is an authorization problem. Unlike a
foreground job which we can always run SU53 after the execution to get
which auth is needed, the log of the background job didn't tell more
detail other than "it is an auth problem". Pls help us with this. is
there a way to find out what is the exactly reason after a background job
failed because of authorization?

thanks.

Answer:
Several solutions:
1) Copy the batch user to a dialogue user, then logon and run the job. You will then have your error online and maybe the SU53 you are looking for.
2) Check S_PROGRAM value for the batch user. Maje sure the batch user has activity BTCSUBMIT for the program auth group. Have you checked the job log in SM37?? You can usually drill-down to see some type of error. Common errors are S_PROGRAM and S_DATASET authotizations' missing.

Answer:
You can also run an authorization trace from ST01 for the "job step executor" (the background user) -- not the batch job scheduler, unless if they're run by the same people.

Also -- make sure you run ST01 on the exact application server the batch job is running to capture the trace.

Answer:
Tried to run the job online, it went through w/o problem.

Tried it in background again, failed with same authorization problem.

Does this make sense for you guys? Should running online and running in background have the same authorization check?