Production and Operations Analysis, Seventh Edition
7th Edition
ISBN: 9781478623069
Author: Steven Nahmias, Tava Lennon Olsen
Publisher: Waveland Press, Inc.
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Chapter 9.8, Problem 19P
a.
Summary Introduction
Interpretation: The sequence required for processing the jobs resulting in minimizing the expected time of completion of all the said jobs.
Concept Introduction:
LEPT rule: LEPT when expanded is the longest expected processing time. According to this rule, completion time can be derived by arranging the jobs in decreasing order.
b.
Summary Introduction
Interpretation: The start and end times of each job should be computed when the job times are deterministic.
Concept Introduction:
Make span time: This is the time required to complete the last job before leaving the system.
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Students have asked these similar questions
A computer center has two identical computers for batch processing. Thecomputers are used as parallel processors. Job times are estimated by the user, but experience has shown that an exponential distribution gives an accurate description of the actual job times. Suppose that at a point in time there are eight jobs remaining to be processed with the following expected job times (expressed in minutes):Job 1 2 3 4 5 6 7 8Expected time 4 8 1 50 1 30 20 6a. In what sequence should the jobs be processed in order to minimize theexpected completion time of all eight jobs (i.e., the makespan)?b. Assume that computer A is occupied with a job that has exactly two minutes of processing time remaining and computer B is idle. If job times are deterministic, show the start and end times of each job on each computer using the sequence derived in part (a).
At the campus copy shop, six jobs have arrived in the order shown (A, B, C, D, E, and F) at the beginning of the day 1 (today, which is a work day). All of the jobs are due at various times today. Your job is to evaluate four common sequencing rules.
JOB
DUE (IN HOURS)
DURATION (HOURS REQUIRED)
A
8
(this job is due in 8 hours)
1.65
B
5.5
(this job is due in 5.5 hours)
1.20
C
4.5
(this job is due after lunch in 4.5 hours)
0.85
D
6
(this job is due in 6…
Given the following information on job times and due dates.
Job
Job Time(Hours)
Due Date(Hours)
a
3.5
7
b
2.0
6
c
4.5
18
d
5.0
22
e
2.5
4
f
6.0
20
a-1. Determine the optimal processing sequence using (1) First come, first served, (2) Shortest processing time, (3) Earliest due date, and (4) Critical ratio.
Sequence for First come, first served
Sequence for Shortest processing time
Sequence for Earliest due date
Sequence for Critical ratio
a-2. For each method, find the average job flow time and the average job tardiness. (Round your answers to 2 decimal places.)
First Come, FirstServed
Shortest ProcessingTime
Earliest Due Date
Critical Ratio
Average flow time
Average job tardiness
Chapter 9 Solutions
Production and Operations Analysis, Seventh Edition
Ch. 9.5 - Prob. 1PCh. 9.5 - Prob. 2PCh. 9.5 - Prob. 3PCh. 9.5 - Prob. 4PCh. 9.5 - Prob. 5PCh. 9.6 - Prob. 6PCh. 9.6 - Prob. 7PCh. 9.6 - Prob. 8PCh. 9.6 - Prob. 9PCh. 9.6 - Prob. 10P
Ch. 9.7 - Prob. 11PCh. 9.7 - Prob. 12PCh. 9.7 - Prob. 13PCh. 9.7 - Prob. 14PCh. 9.7 - Prob. 15PCh. 9.7 - Prob. 16PCh. 9.7 - Prob. 17PCh. 9.8 - Prob. 18PCh. 9.8 - Prob. 19PCh. 9.8 - Prob. 20PCh. 9.8 - Prob. 21PCh. 9.8 - Prob. 22PCh. 9.9 - Prob. 23PCh. 9.9 - Prob. 24PCh. 9.9 - Prob. 25PCh. 9.10 - Prob. 27PCh. 9.10 - Prob. 28PCh. 9.10 - Prob. 29PCh. 9 - Prob. 30APCh. 9 - Prob. 31APCh. 9 - Prob. 32APCh. 9 - Prob. 33APCh. 9 - Prob. 34APCh. 9 - Prob. 35APCh. 9 - Prob. 36APCh. 9 - Prob. 37APCh. 9 - Prob. 38APCh. 9 - Prob. 39APCh. 9 - Prob. 40APCh. 9 - Prob. 41APCh. 9 - Prob. 42APCh. 9 - Prob. 43APCh. 9 - Prob. 44APCh. 9 - Prob. 45APCh. 9 - Prob. 46APCh. 9 - Prob. 47AP
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