6) Alice's Alterations has eight jobs to be completed and only one sewing machine (and one sewing machine operator). The following jobs are waiting to be scheduled for the sewing machine. The letter of the alphabet indicates the sequence in which the jobs arrived. It is now the beginning of Day 5 and jobs are due at the end of the promised day.
|
Job
|
Processing Time (in days)
|
Promised Time (days from Day 0)
|
|
A
|
5
|
10
|
|
B
|
8
|
15
|
|
C
|
6
|
15
|
|
D
|
3
|
20
|
|
E
|
10
|
25
|
|
F
|
14
|
40
|
|
G
|
7
|
45
|
|
H
|
4
|
50
|
a) Prioritize these jobs by CR (Critical Ratio=remaining time to promised time / remaining processing time) and Slack (remaining time to promised time - remaining processing time).
b) Evaluate your priority sequences in a) on average flow time from now, average lateness (with no credit for being early) and average days early (with zero days early for a job that is late).
c) Based on your analysis in b), what sequencing scheme would you select? Why?