Operations Management
11th Edition
ISBN: 9780132921145
Author: Jay Heizer
Publisher: PEARSON
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Chapter D, Problem 7P
Question
• • D.7 Automobiles arrive at the drive-through window at the downtown Baton Rouge, Louisiana, post office at the rate of 4 every 10 minutes. The average service time is 2 minutes. The Poisson distribution is appropriate for the arrival rate and service times are exponentially distributed.
- a. What is the average time a car is in the system?
- b. What is the average number of cars in the system?
- c. What is the average number of cars waiting to receive service?
- d. What is the average time a car is in the queue?
- e. What is the probability that there are no cars at the window?
- f. What percentage of the time is the postal clerk busy?
- g. What is the probability that there are exactly 2 cars in the system?
- h. By how much would your answer to part (a) be reduced if a second drive-through window, with its own server, were added?
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Question 4
A petrol station in the capital Kingstown has a single pump manned by one attendant.
Vehicles arrive at the rate of 20 customers per hour and petrol filling takes 2 minutes on an
average. Assume the arrival rate is Poisson probability distribution and service rate is
exponentially distributed. Arrivals tend to follow a Poisson distribution, and service times
tend to be exponential. The attendant is paid $10 per hour, but because of lost goodwill and
sales, station loses about $15 per hour of customer time spent waiting for the attendant to
service and order.
Part A
Answer the following questions based on single channel model:
a. What is the probability that no customers are in the system (Po)?!
b. What is the average number of customers waiting for service (Lq)?
c. What is the average number of customers in the system (L)?…………..
d. What is the average time a customer waits for service (Wq)?!
e. What is the average time in the system (W)?❤❤
s
f. What is the probability that a…
Q.2) Partially completed products arrive at a workstation in a manufacturing operation at a mean
rate of 40 per hour (Poisson distributed). The processing time at the workstation averages 1.2
minutes per unit (exponentially distributed). The manufacturing company estimates that each
unit of in process inventory at the workstation costs $31 per day (on the average). However, the
company can add extra employees and reduce the processing time to 0.90 minute per unit at a
cost of $52 per day. Determine whether the company should continue the present operation or
add extra employees.
Question 8.1
The computer lab at State University has a help desk to assist students working on computer
spreadsheet assignments. The students patiently form a single line in front of the desk to wait for help.
Students are served based on a first-come, first-served priority rule. Students arrive at the help desk at
the rate of 4 every 10 minutes. The average service time is 2 minutes. The Poisson distribution is
appropriate for the arrival rate and service times are exponentially distributed.
Chapter D Solutions
Operations Management
Ch. D - Prob. 1DQCh. D - Prob. 2DQCh. D - Question 3. Name the three factors that govern the...Ch. D - Prob. 4DQCh. D - Prob. 5DQCh. D - Prob. 6DQCh. D - Prob. 7DQCh. D - Prob. 8DQCh. D - Prob. 9DQCh. D - Question 10. Describe the behavior of a waiting...
Ch. D - Question 11. Discuss 1he likely outcome of a...Ch. D - Prob. 12DQCh. D - Prob. 13DQCh. D - Prob. 14DQCh. D - Question 15. What happens if two single-server...Ch. D - Prob. 16DQCh. D - Prob. 17DQCh. D - Prob. 1PCh. D - Prob. 2PCh. D - Question D.3 Paul Fenster owns and manages a...Ch. D - Prob. 4PCh. D - Prob. 5PCh. D - Prob. 6PCh. D - Question D.7 Automobiles arrive at the...Ch. D - Question D.8 Virginias Ron McPherson Electronics...Ch. D - Question D.9 Neve Commercial Bank is the only...Ch. D - Question D.10 Beate Klingenberg manages a...Ch. D - Question D.11 Bill Youngdahl has been collecting...Ch. D - Question D.12 The wheat harvesting season in the...Ch. D - Prob. 13PCh. D - Prob. 14PCh. D - Prob. 15PCh. D - Prob. 16PCh. D - Prob. 17PCh. D - Prob. 18PCh. D - Question D.19 One mechanic services 5 drilling...Ch. D - Prob. 20PCh. D - Prob. 21PCh. D - Prob. 22PCh. D - Prob. 23PCh. D - Prob. 24PCh. D - Question New England Foundry For more than 75...Ch. D - Prob. 1.2CSCh. D - New England Foundry For more than 75 years, New...Ch. D - Question The Winter Park Hotel Lori Cook, manager...Ch. D - Question The Winter Park Hotel Lori Cook, manager...
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