Is a batch application looping?

If you suspect that a batch or TSO application is looping, use the console to issue the z/OS command

DISPLAY JOBS,A (for a batch application) or

DISPLAY TS,A (for a TSO application). Note the CT values from the data displayed, and repeat the command.

If any task shows a significant increase in the CT value, it might be that the task is looping. You could also use SDSF DA, which shows you the percentage of CPU that each address space is using.