The CPU scheduler chooses which ready process runs next.
1Algorithms
FCFS: in order of arrival (non-preemptive)
SJF: shortest burst first (optimal average waiting time); SRTF is its preemptive form
Priority: highest priority first (ageing prevents starvation)
Round Robin: each process gets a time quantum in turn
2Measures
Turnaround time = completion − arrival
Waiting time = turnaround − burst
Response time = first run − arrival