First-Come,First-Served Scheduling:

Process：Burst Time:

P1      15

P2       3

P3       6

P4       6

The average waiting time is (0+15+18+24)/4 = 14.25 milliseconds

 

Shortest-Job-First Scheduling:

Process：Burst Time:

P1      15

P2       3

P3       6

P4       6

The average waiting time is (0+3+9+15)/4 = 6.75 milliseconds

 

Shortest-Remaining-Time-First Scheduling:

Process：Arrival Time: Burst Time:

P1         0         15

P2         1          3

P3         2          6

P4         3          7

The average waiting time is (17-1+1-1+4-2+10-3)/4 = 6.25 milliseconds

 

Priority Scheduling:

Process： Burst Time: Priority:

P1        15       3

P2         3       1

P3         6       4

P4         7       2

The average waiting time is (0+3+10+25)/4 = 9.5 milliseconds

 

Round-Robin Scheduling:

Process： Burst Time:

P1        15

P2         3

P3         6

P4         7

Use a time quantum of 6 milliseconds,

The average waiting time is (6+9+27-6+28-12)/4 = 13 milliseconds