Loose-leaf for Operations Management (The Mcgraw-hill Series in Operations and Decision Sciences)
12th Edition
ISBN: 9781259580093
Author: William J Stevenson
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 18, Problem 13P
a)
Summary Introduction
To determine: Whether the third crew member will be economical.
b.
Summary Introduction
To determine: Would the fourth member be justifiable.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Trucks arrive at the loading dock of a wholesale grocer at the rate of 1.2 per hour. A single crewconsisting of two workers can load a truck in about 30 minutes. Crew members receive $10 perhour in wages and fringe benefits, and trucks and drivers reflect an hourly cost of $60. The manager is thinking of adding another member to the crew. The service rate would then be 2.4 trucksper hour. Assume rates are Poisson.a. Would the third crew member be economical?b. Would a fourth member be justifiable if the resulting service capacity were 2.6 trucks per hour?
A server operates with 90 % utilization. Coefficient of variation of service process is 0.6. Coefficient of variation of arrival process is 0.8. Average processing time is 4 minutes. What is the average time a customer spends in the system using the single server queuing model ? Show all formulas used, calculations and results.
A vending machine dispenses hot chocolate or coffee. Service time is 30 seconds per cup and is constant. Customers arrive at a mean rate of 76 per hour, and this rate is Poisson-distributed.
a.
Determine the average number of customers waiting in line. (Round your answer to 2 decimal places.)
Average number of customer
b.
Determine the average time customers spend in the system. (Do not round intermediate calculations. Round your answer to 2 decimal places.)
Average time
minutes
c.
Determine the average number of customers in the system. (Do not round intermediate calculations. Round your answer to 2 decimal places.)
Average number
customers
Chapter 18 Solutions
Loose-leaf for Operations Management (The Mcgraw-hill Series in Operations and Decision Sciences)
Ch. 18 - Prob. 1DRQCh. 18 - Why do waiting lines form even though a service...Ch. 18 - Prob. 3DRQCh. 18 - Prob. 4DRQCh. 18 - What approaches do supermarkets use to offset...Ch. 18 - Prob. 6DRQCh. 18 - Prob. 7DRQCh. 18 - Prob. 8DRQCh. 18 - Prob. 9DRQCh. 18 - Prob. 1TS
Ch. 18 - Prob. 2TSCh. 18 - Prob. 3TSCh. 18 - Prob. 1CTECh. 18 - Prob. 2CTECh. 18 - Prob. 3CTECh. 18 - The owner of Eat Now Restaurant implemented an...Ch. 18 - Prob. 5CTECh. 18 - Prob. 1PCh. 18 - Prob. 2PCh. 18 - Prob. 3PCh. 18 - Prob. 4PCh. 18 - Prob. 5PCh. 18 - Prob. 6PCh. 18 - Prob. 7PCh. 18 - Prob. 8PCh. 18 - Prob. 9PCh. 18 - Prob. 10PCh. 18 - Prob. 11PCh. 18 - Prob. 12PCh. 18 - Prob. 13PCh. 18 - Prob. 14PCh. 18 - Prob. 15PCh. 18 - A priority waiting system assigns arriving...Ch. 18 - Prob. 17PCh. 18 - Prob. 18PCh. 18 - Prob. 1CQ
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, operations-management and related others by exploring similar questions and additional content below.Similar questions
- Benny's arcade has six video game machines. The average time between machine failures is 50 hours. Jimmy, the maintenance manager can repair a machine in 5 hours on average. The machines have an exponential failure distribution, and Jimmy has an exponential service-time distribution. a. Jimmy's utilization is? b. what is the average number of machines out of service, that is, waiting to be repaired or being repaired? c. what is the average time a machine is out of service?.arrow_forwardA vending machine dispenses hot chocolate or coffee. Service time is 15 seconds per cup and is constant. Customers arrive at a mean rate of 55 per hour, and this rate is Poisson-distributed. a. Determine the average number of customers waiting in line. (Round your answer to 2 decimal places.) Average number of customer b. Determine the average time customers spend in the system. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Average time minutes c. Determine the average number of customers in the system. (Do not round intermediate calculations. Round your answer to 2 decimal places.)arrow_forwardConsider a bank with two tellers. An average of 2 customers per hour arrive at the bank and wait in a single línea for an idle teller. The average time it takes to serve a customer is triangular (x1=1, y1=0), (x2=4, y2=2/3) Assume that inter-arrival times and services time is exponential. Develop the service (ST) equation? a. Y=2x-22/6B. Y=2x-22/3C. Y=22/3x-2/3D. Y=2x-3/22arrow_forward
- [Queuing Theory - Operation research] The take-out counter at an ice-cream parlor is serviced by one attendant. Customers arrive according to a Poisson process, at a mean arrival rate of 30 per hour. They are serviced on a FCFS basis, and because of the quality of the ice cream, they are willing to wait if necessary. The service time per customer appears to be exponentially distributed, with a mean of 1.5 minutes. Determine the following: (a) probability that the system is idle (b) average number of customers in the system (c) amount of time a customer should expect to wait before service (d) probability that a customer will have to spend more than 15 minutes in the queuearrow_forwardNeed helparrow_forwardA single server queuing system has an average service time of 10 minutes per customer, which is exponentially distributed. The manager is thinking of converting to a system with a constant service time of 10 minutes. The average arrival rate will remain the same. The effect will be to: Select one: a. increase utilization. b. decrease utilization. c. not have any effect since the service time is unchanged. d. increase the average waiting time. e. decrease the average waiting time.arrow_forward
- A waiting-line system that meets the assumptions of M/M/S has λ = 5, μ = 4, and M = 2. For these values, Po is approximately 0.23077, and Ls is approximately 2.05128. What is the average time a unit spends in this system? Select one: a. approximately 0.8013 b. approximately 0.4103 c. Cannot be calculated because λ is larger than μ. d. approximately 0.2083 e. approximately 0.1603arrow_forwardIn an M/MA queueing system, the arrival rate is 4 customers per hour and the service rate is 6 customers per hour. If the service process is automated (resulting in no variation in service times but the same service rate), what will be the resulting performance measurements? (Round your answers to 3 decimal places.) a. What is the utilization? Utilization b. What is the expected number of customers in the system (L)? Number of customers c. What is the expected waiting time (in hours) for the system (W)? Waiting time(in hours) d. What is the expected number of customers in the queue(La)? < Prev 2 of 5 Next raw lillarrow_forwardConsider a bank branch that has three distinct customer arrival patterns throughout the day, as measured by average arrival rates (below). Morning (8:30 - 11:30): arrival 1 = 47 per hour. %3D Lunch (11:30 - 1:30): arrival 2 = 70 per hour. Afternoon (1:30 - 4:00): arrival 3 = 30 per hour. Regardless of the time of day, the average time it takes for a teller to serve customers is 3.17 minutes. Because of competition with other banks in the area, management has developed an internal goal to keep the average customer wait before service to be less than 4 minutes. With that in mind, answer the following: a. During the morning period, what is the minimum number of tellers that the bank needs to hire to achieve the 4-minute service goal mentioned above? [ Select] b. During lunch, what is the minimum number of tellers that the bank needs to hire to achieve the 4 minute service goal mentioned above? [ Select ] c. In the afternoon, what is the minimum number of tellers that the bankarrow_forward
- Trucks arrive at a warehouse at a rate of 15 per hour during business hours. Crews canunload the trucks at a rate of five per hour. The high unloading rate is due to cargo beingcontainerized. Recent changes in wage rates have caused the warehouse manager to reexamine the question of how many crews to use. The new rates are: Crew and dock cost is$100 per hour; truck and driver cost is $120 per hour.arrow_forwardPlease do not give solution in image formate thanku. λ= 4 customers per hour; μ = 5 customers per hour; M= 1 An average of 20 customers arrive at a service center each hour. There are two servers on duty, and each can process 12 customers per hour. a) What is the system utilization? b) What is the average waiting time for customers who actually have to wait? c) What is the average time customers wait in line for service?arrow_forwardVirginia's Ron McPherson Electronics Corporation retains a service crew to repair machine breakdowns that occur on an average of λ = 3 per 8-hour workday (approximately Poisson in nature). The crew can service an average of μ = 10machines per workday, with a repair time distribution that resembles the negative exponential distribution. a) The utilization rate of this service system? b) The average downtime for a broken machine? c) Average number of machines waiting to be serviced at any given time? d) The probability that more than 1 machine is in the system? The probability that more than 2 machine is in the system? The probability that more than 3 machine is in the system? The probability that more than 4 machine is in the system?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Practical Management ScienceOperations ManagementISBN:9781337406659Author:WINSTON, Wayne L.Publisher:Cengage,
Practical Management Science
Operations Management
ISBN:9781337406659
Author:WINSTON, Wayne L.
Publisher:Cengage,