Answer
It depends on whether the jobs that typically run in that specific queue are safe to execute in parallel, or need to run sequentially to preserve a workflow dependency — a queue whose jobs can safely run concurrently benefits from more processes, while a queue whose jobs could conflict if run at the same time (or that only ever holds one job at a time) doesn't need more than one. When sizing the Oracle job_queue_processes parameter to accommodate whatever total you land on, a reasonable formula is: Oracle-reserved processes (commonly kept at 5) + a small buffer (commonly kept at 3) + the total number of processes assigned across all your IFS batch queues combined.