HRN reduces bias against longer jobs. Multilevel Feedback Queues - processes move from highest priority to lowest as each time quantum expires. Fair Share Scheduling - supports process scheduling across multiple users as well as multiple processes. A single user or related group of users are provided a prespecified rate of system resources at a fixed cost. The FSS divides system resource capacity into portions, which are then allocted by process schedulers assigned to various fair share groups.
Highest priority is given to jobs with the least CPU usage recently.
N seconds where N is the number of active jobs in the system over the last minute.