How does SYSB-AJR get control of the batch job step?
The operating system gives SYSB-AJR control of a batch step if the operating system finds the SUBSYS=SYSB parameter on a DD statement. One way to add this parameter to a DD statement is by implementing a JES2 exit 6 that HW provides. This exit uses the SYSB-AJR control file to match jobname, job step, proc step, program, and DD name to determine which DD statements get the parameter. Another way is to modify the JCL and add SUBSYS=SYSB to the DD statement manually.