Scheduling Criteria

• CPU Utilization (System centric)
  • Keep CPU as much busy as possible
• Throughput (System centric)
  • Number of processes completed/time
• Turnaround time (Process centric)
  • Real time taken to complete a process
• Waiting time (Process centric)
  • How much time a process is in ready queue
• Response time (Process centric)
  • Factor for an interactive process
• Deadline (Real time behavior)
  • Time guarantee to schedule a task.

Scheduling Algorithms

• First Come First Serve (FCFS)
  • Simplest implementation
  • No preemption
• Shortest Job First (SJF)
  • Optimal scheduling algorithm
  • Minimum Average Waiting Time
  • Difficulty: To know the time that it will take
  • Batch systems: A good choice.