Process |
Burst |
Priority |
Arrival Time |
P1 |
8 |
4 |
0 |
P2 |
6 |
1 |
2 |
P3 |
1 |
2 |
2 |
P4 |
9 |
2 |
1 |
P5 |
3 |
3 |
3 |
|
First Come First Served
0 8 17 23 24 27
Avg. Wait = 0+8‐1+17‐2+23‐2+24‐3 = 0+7+15+21+21=64/5 = 12.8 AVG TAT = 8+17‐1+23‐2+24‐2+27‐3 = 8+16+21+22+24=91/5=18.2
Non‐Preemptive Priority
0 8 14 15 24 27
Avg. Wait = 8‐2+14‐2+15‐1+24‐3 = 6+12+14+21 = 53/5=10.6ms AVG TAT = 8+14‐2+15‐2+24‐1+27‐3 = 8+12+13+23+24=80/5=16ms
Preemptive Priority
0 1 2 8 9 17 20 27
Avg. Wait Time = 0+20‐1+2‐2+8‐2+9‐2+17‐3 = 0+19+0+6+7+14 = 46/5=9.2ms AVG TAT = 27+8‐2+9‐2+16+20‐3 = 73/5 = 14.6ms
Round Robin (1ms Quantum)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
P1 |
P4 |
P2 |
P3 |
P5 |
P1 |
P4 |
P2 |
P5 |
P1 |
P4 |
P2 |
P5 |
P1 |
P4 |
P2 |
P1 |
P4 |
P2 |
P1 |
P4 |
P2 |
P1 |
P4 |
P1 |
P4 |
P4 |
Wait Time P
1 = 0+4+3+3+2+2+1+1 = 16 Wait Time P2 = 0+4+3+3+2+2+2+1 = 17
Wait Time P3 = 1
Wait Time P4 = 4+4+3+2+3+2+1 = 19
Wait Time P5 = 1+3+3 = 7 Avg Wait Time = 60/5 = 12ms
Avg TAT =25+21+2+26+10 = 84/5 = 16.8
Algorithm |
Avg Wait |
Avg TAT |
FCFS |
12.2 |
18.2 |
NonP Priority |
10.6 |
16 |
Prem Priority |
9.6 |
14.6 |
RR |
2 |
6.8 |
> Computer and Education