JES2 can increase the priority of a job's output based on the time since the output was created. You define this ability by specifying PRTYHIGH=, PRTYLOW=, and PRYORATE= parameters on the OUTDEF initialization statement.

PRTYHIGH= specifies the highest priority which output can achieve through automatic priority aging. PRTYLOW= specifies the lowest priority for a job to be eligible for automatic priority aging. PRYORATE= specifies the number of times in a 24-hour period that the system will increase a job's priority (subject to the PRTYHIGH= limit) by one. PRYORATE= has a default of 0, which means the system will not priority age any output.

For example, if PRTYRATE=48, PRTYLOW=100, and PRTYHIGH=200, then all jobs with priorities of 100 to 199 will have their priority increased by 1 every 30 minutes (that is, 24 hours / PRTYRATE of 48 = 30 minutes) until the job priority reaches priority 200.

You set the lower priority limit, PRTYLOW=, to ensure that low priority output does not reach priority levels higher than new, more important output entering the system. In the previous example, all output with priorities between 1 and 99 (inclusive) will not priority age.

You set the upper priority limit, PRTYHIGH=, to ensure that high priority output maintains its importance, and doesn't compete with output that achieved its priority from length of time in the system. In the previous example, output with priority 200 or higher, will not priority age but maintains higher priority than any output that can priority age. See Figure 1 for a graphic representation of the priority range setting for output.

Figure 1. Example of the interaction of priority–aging parameters PRTYHIGH, PRTYLOW, and PRYORATE on OUTDEF statement