Use Johnson's rule to determine the optimal sequencing for the five jobs to be processed on two machines in a fixed order (Machine 1 before Machine 2). The processing times are given in the table below.
Job |
Machine 1 |
Machine 2 |
L |
10 |
2 |
M |
5 |
4 |
N |
7 |
5 |
O |
3 |
6 |
P |
1 |
7 |
** Please show excel steps so i can see if I did this right** thanks
What is the optimal sequence?
What is the total flow time for this sequence?
Answer
Pls. see the details below:
Processing times | ||
Job | Machine 1 | Machine 2 |
L | 10 | 2 |
M | 5 | 4 |
N | 7 | 5 |
O | 3 | 6 |
P | 1 | 7 |
look for the lowest time | 1 | =MIN(B3:C7) |
which is Job P Machine 1 | ||
Next step | ||
Look for next min out of L M N O | 2 | =MIN(B3:C6) |
which is Job L Machine 2 | ||
so we place it at the end as Machine 2 | ||
Next step | ||
Look for next min out of M N O | 3 | =MIN(B4:C6) |
which is Job O Machine 1 | ||
so place at the 2nd position | ||
Next step | ||
Look for next min out of M N | 4 | |
which is Job M Machine 2 | ||
so placed at 2nd last position | ||
Optimal sequence is | ||
P,O,N, M,L |
Optimal Sequence | ||||
P | O | N | M | L |
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 | |
Machine 1 | P | O | N | M | L | |||||||||||||||||||||
Machine 2 | P | O | N | M | L |
Excel
If you liked my answer thumbs up pls.
Get Answers For Free
Most questions answered within 1 hours.