PRIORITYGOAL specifies a list of service class names of 8 characters or less that are used with the nice(), setpriority(), and chpriority() callable services when the system is running in goal mode.

If you are using your system to run a critical real-time application program, specify a list of service class names. It is difficult to run both real-time application programs and general users on the same z/OS UNIX system because you cannot restrict any set of users from access to the nice() and setpriority() functions. For more information, see Controlling dispatching priorities.