Question

Part 4.   Questions 6,7. [ Use Video-1 under Scheduling heading. ]

[Note: The order of jobs in a schedule is 1^st,2^nd,3^rd,4^th,5^th, for A,B,C,D,E, respectively.]

The jobs A,B,C,D,E, arrived in that order to be processed on two machines.

Job	A	B	C	D	E
Time on Machine 1	45	53	63	31	75
Time on Machine 2	42	65	61	53	77

Question 6. Which is the Johnson’s Rule schedule?

     (A) ‘ACEBD’     (B) ‘DCABE’     (C) ‘DBECA’     (D) ‘DABEC’   (E) none of the above

Question 7. Consider the FIFO schedule of (A,B,C,D,E).

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

Statement 1. The total time of completion is 344

Statement 2. The flow time of job D is 245

Statement 3. The total queue time of job C is 100

Statement 4. The total idle time of machine 2 is 45

. . .

Answer 1

Question 6

Shortest processing time (time)	Job	Operation (1 Or 2)	Sequence
31	D	Operation 1	First
42	A	Operation 2	Last
53	B	Operation 1	Second
61	C	Operation 2	Second last
75	E	Operation 1	Third

Now the sequence is D-B-E-C-A

Option (C)

.

Question 7

Job	Start Hour	End Hour	Idle Time	Start Hour	End Hour	Idle Time
A	0	45	0	45	87	45
B	45	98	0	98	163	11
C	98	161	0	163	224	0
D	161	192	0	224	277	0
E	192	267	0	277	354	0
Total			0

Statement 1. The total time of completion is 344

Statement 2. The flow time of job D is 245

Statement 3. The total queue time of job C is 100

Statement 4. The total idle time of machine 2 is 45

All statements are false

Option (A)