In the Job Overview transaction SM37, select the job that has finished and enter jdbg in the command field. The Debugger will start. It will simulate the exact scenario with the same selection screen values, and the system variable SY-BATCH will be set to X (abap_true).
SY-BATCH is the system variable that indicates that an application is running in the background. Some programs are coded to behave differently depending on its value; it is set to X to ensure that the program will behave as if it was running in the background.
