January 16, 2010

Compute the the average turnaround time of the following process scheduling algorithm.

 Arrival Time: 0 1 2 3 4 5 6 7 8 9 10

Job Name:A B C D E F G H I J K 

CPU Cycle: 5 2 8 4 3 1 2 9 7 3 4

a. First Come First Come First Serve Algorithm

JOB A	JOB B	JOB C	JOB D	JOB D	JOB E	JOB F	JOB G	JOB H	JOB I	JOB K
0-5	7	15	19	27	23	25	34	41	44	48

ATT=(5+7+15+19+22+23+25+34+41+44+48)/11=25.73

b. Shortest Job Next

JOB F	JOB B	JOB G	JOB E	JOB J	JOB D	JOB K	JOB A	JOB I	JOB C	JOB H
0-1	3	5	8	11	15	19	24	31	39	48

ATT=(1+3+5+8+11+15+19+24+31+39+48)/11=18.55

c. Shortest Remaining Time

JOB A	JOB B	JOB C	JOB D	JOB F	JOB G	JOB E	JOB H	JOB I	JOB J	JOB A	JOB K
0-3	3	4	8	9	11	13	14	15	18	22	26

ATT=(22+2+2+5+9+5+40+24+9+16)/11=12.64

 d. Round Robin 

JOB A	JOB B	JOB C	JOB D	JOB E	JOB F	JOB G	JOB H	JOB I	JOB J	JOB K	JOB A
0-2	4	6	8	10	11	13	15	17	19	21	23
JOB J	JOB K	JOB A	JOB C	JOB H	JOB I	JOB C	JOB H	JOB I	JOB H
33	35	36	38	40	42	44	46	47	48

 ATT=(36+34+42+24+6+7+41+39+24+25)/11=24.64