Final answer:
Shortest Job Next (SJN) is a scheduling policy in which the process with the shortest expected processing time is selected next, and the currently running process is preempted if a shorter process becomes ready.
Step-by-step explanation:
The scheduling policy described in the question is known as Shortest Remaining Time First (SRTF). This is a preemptive version of the shortest job first (SJF) scheduling algorithm. In SRTF, the scheduler selects the process with the shortest expected processing time. If a new process arrives or becomes ready to execute which has a shorter expected completion time than the currently running process, the current process is preempted, and the CPU is assigned to the new process. This approach ensures that shorter processes are handled quickly, potentially reducing wait time and improving system responsiveness.
However, one of the downsides of this approach is the possibility of starvation of longer processes if shorter processes frequently enter the system. To mitigate the risk of starvation, various algorithms can be used, such as aging, which gradually increases the priority of longer-waiting processes.