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Running processes are those that use a processor resource and are marked as ' running '.

Processes that are ready to be assigned to a processor, when there is no free processor are placed in the ready queue.

Processes may be assigned a “ Declared ” or “ Visible ” priority, generally 50 as the default, but can be from 0 to 99 for user processes.

System processes may be assigned the higher values.

Note that this numerical priority is secondary to an overall priority, which is based on the task type.

Processes that are directly part of the operating system, called Independent Runners, have the highest priority regardless of numeric priority value.

Next come processes using an MCP lock, then Message Control Systems such as CANDE.

Then Discontinued processes.

Then Work Flow Language jobs.

Finally come user processes.

At a lower level there is a Fine priority intended to elevate the priority of tasks that do not use their full processor slice.

This allows an IO bound task to get processor time ahead of a processor bound task on the same declared priority.