Question

Part 3. Questions 3,4,5. [ Use Video-2 under Scheduling heading. ]

[Note: The order of jobs in a schedule ABCDE is 1^st,2^nd,3^rd,4^th,5^th, respectively.]

Five jobs arrived to be processed with the processing times and due dates.

Present Date=	300
Work Order	A	B	C	D	E
Processing Times (Days)	14	5	40	12	7
Due Date	167	163	195	191	161

. . .

Question 3. The FIFO schedule is “ABCDE” (where job “A” is the first job) and the LIFO schedule is “EDCBA” (where job “E” is the first job).

Consider the schedules based on the sequencing rules: Minimum Processing Time (MPT); Earliest Due Date (EDD); Minimum Slack Time (MST); and Minimum Critical Ratio (MCR). How many of the schedules are correct?     (A) 0   (B) 1   (C) 2   (D) 3   (E) 4

The schedule based on the MPT sequencing rule is BEDAC

The schedule based on the EDD sequencing rule is BAEDC

The schedule based on the MST sequencing rule is AEBCD

The schedule based on the MCR sequencing rule is BEADC

. . .

Question 4.   Consider the MPT schedule.

How many statements are correct?   (A) 0   (B) 1   (C) 2   (D) 3   (E) 4

Statement 1. The total processing time of the schedule is 157

Statement 2. The total flow of the schedule is 78

Statement 3. The total lateness of the schedule is 157

Statement 4. The Makespan of the schedule is 78

. . .

Question 5.   Consider the FIFO schedule.

How many statements are correct?   (A) 0   (B) 1   (C) 2   (D) 3   (E) 4

Statement 1. The flow of job B is 5

Statement 2. The lateness of job C is 164

Statement 3. The date of completion of job D is 180

Statement 4. The queue time of job E is 78

. . .

Answer 1

Compute Slack Time and Critical Ratio for each job as under:

Slack Time = Due Date - Processing Time

Critical Ratio = Due Date / Processing Time

Work Order	A	B	C	D	E
Processing Times (Days)	14	5	40	12	7
Due Date	167	163	195	191	161
Slack Time	153	158	155	179	154
Critical Ratio	11.92857	32.6	4.875	15.91667	23

Question 3. The FIFO schedule is “ABCDE” (where job “A” is the first job) and the LIFO schedule is “EDCBA” (where job “E” is the first job). Consider the schedules based on the sequencing rules: Minimum Processing Time (MPT); Earliest Due Date (EDD); Minimum Slack Time (MST); and Minimum Critical Ratio (MCR). How many of the schedules are correct?     (A) 0   (B) 1 (C) 2   (D) 3   (E) 4 The schedule based on the MPT sequencing rule is BEDAC The schedule based on the EDD sequencing rule is BAEDC The schedule based on the MST sequencing rule is AEBCD The schedule based on the MCR sequencing rule is BEADC . . . Using MPT rule, jobs are scheduled as per ascending order of their Processing Time. So, the given schedule, i.e.  BEDAC is correct. Using EDD rule, jobs are scheduled as per ascending order of their Due Date. So, the given schedule, i.e. BAEDC is incorrect. The correct schedule is EBADC Using MST rule, jobs are scheduled as per ascending order of their Slack Time. So, the given schedule, i.e. AEBCD is incorrect. The correct schedule is AECBD Using MCR rule, jobs are scheduled as per ascending order of their Critical Ratio. So, the given schedule, i.e. BEADC is incorrect. The correct schedule is CADEB Therefore, only 1 schedule is correct, i.e. MPT ANSWER: (B) 1 . . .

Question 4.   Consider the MPT schedule. How many statements are correct?   (A) 0   (B) 1   (C) 2   (D) 3   (E) 4 Statement 1. The total processing time of the schedule is 157 Statement 2. The total flow of the schedule is 78 Statement 3. The total lateness of the schedule is 157 Statement 4. The Makespan of the schedule is 78 . . . MPT schedule is following: Work Order Processing Times (Days) Due Date Flow Time = Running sum of processing time Completion time = 300 + Flow time Lateness = Completion time - Due Date B 5 163 5 305 142 E 7 161 12 312 151 D 12 191 24 324 133 A 14 167 38 338 171 C 40 195 78 378 183 Total 78 157 780 Statement 1 is incorrect, because total processing time of the schedule is 78 Statement 2 is incorrect, because total flow time of the schedule is 157 Statement 3 is incorrect, because total lateness is 780 and average lateness = 780/5 = 156 Statement 4 is correct, as Makespan of the schedule = Sum of processing times of all jobs = 78 Therefore, only one statement is correct. ANSWER: (B) 1 . . .

Question 5.   Consider the FIFO schedule. How many statements are correct?   (A) 0   (B) 1 (C) 2   (D) 3   (E) 4 Statement 1. The flow of job B is 5 Statement 2. The lateness of job C is 164 Statement 3. The date of completion of job D is 180 Statement 4. The queue time of job E is 78 . . . FIFO schedule is following: Work Order Processing Times (Days) Due Date Flow Time Completion time Lateness Queue Time A 14 167 14 314 147 0 B 5 163 19 319 156 14 C 40 195 59 359 164 19 D 12 191 71 371 180 59 E 7 161 78 378 217 71 Total 78 241 864 163 As we see in the above schedule, Only statement 2 is correct ANSWER: (B) 1. . . .