Phases of job processing

The z/OS® base control program and JES2 share responsibility in an System z® system. JES2 is responsible for job entry (input), the base control program for device allocation and actual job running, and finally JES2 for job exit (output).

Figure 1 presents a view of the six phases, followed by a description of each.

Figure 1. Job Processing Phases
The diagram shows the six job processing phases.
The job queues contain jobs:
  • Waiting to run - conversion queue
  • Currently running - execution queue
  • Waiting for their output to be produced - output queue
  • Having their output produced - hard-copy (print/punch) queue
  • Waiting to be purged from the system (following completion of all processing) - purge queue.