Consider the following set of jobs with their arrival times, execution time (in minutes), and deadlines.
|
Job Ids
|
Arrival Time
|
Execution time
|
Deadline
|
|
1
|
0
|
5
|
5
|
|
2
|
1
|
15
|
25
|
|
3
|
3
|
12
|
10
|
|
4
|
7
|
25
|
50
|
|
5
|
10
|
5
|
12
|
Calculate the mean turn-around time, the mean weighted turn-around time and the throughput for SJN.
Chart for Shortest Job next scheduling (SJN)
|
1
|
3
|
5
|
2
|
4
|
|
0 5 17 22 37 62
|
Turnaround time for different jobs is
For job 1, T1 = 5-0=5 unit time
For job 2, T2 = 37-1=36 unit time
For job 3, T3 = 17-3=14 unit time
For job 4, T4 = 62-7=55 unit time
For job 5, T5 = 22-10=12 unit time
Mean turnaround time, Tm = (T1+T2+T3+T4+T5)/5= 122/5= 24.4unit time/job
Throughput= no of process completed per unit time= 5/62= 0.081 jobs/unit time.