This option is most useful if there are limited devices in your environment, but you want certain jobs to have priority access to the devices. A ready job that has a higher priority runs before a ready job that has a lower priority. A ready job that has a higher priority also runs before a ready job that has an earlier scheduled start time.
If multiple jobs are ready to run but must wait for a device to become available, then Backup Exec determines which jobs to run first. To make this determination, Backup Exec reviews the job priority and the scheduled start time of the job.