One mechanic services 7 drilling machines for a steel plate manufacturer. Machines break down on an average of once every 8 working days, and breakdowns tend to follow a Poisson distribution. The mechanic can handle an average of three repair jobs per day. Repairs follow a negative exponential distribution. a) On the average, how many machines are waiting for service? The average number of machines waiting for service is. Round your response to three decimal places.) B.) The average time in the system C.) The average number in line

One mechanic services 7 drilling machines for a steel plate manufacturer. Machines break down on an average of once every 8 working days, and breakdowns tend to follow a Poisson distribution. The mechanic can handle an average of three repair jobs per day. Repairs follow a negative exponential distribution. a) On the average, how many machines are waiting for service? The average number of machines waiting for service is. Round your response to three decimal places.) B.) The average time in the system C.) The average number in line

Practical Management Science

6th Edition

ISBN:9781337406659

Author:WINSTON, Wayne L.

Publisher:WINSTON, Wayne L.

Chapter12: Queueing Models

Section12.5: Analytic Steady-state Queueing Models

Problem 26P

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Benny the Barber owns a one-chair shop. At barber college, they told Benny that his customers would exhibit a Poisson arrival distribution and that he would provide an exponential service distribution. His market survey data indicate that customers arrive at a rate of 4.0 per hour. It will take Benny an average of 11 minutes to give a haircut. Based on these figures, find the following:a. The average number of customers waiting. (Round your intermediate calculations to 3 decimal places and final answer to 2 decimal places.) b. The average time a customer waits. (Round your answer to 2 decimal places.) c. The average time a customer is in the shop. (Round your intermediate calculations to 3 decimal places and final answer to 1 decimal place.) d. The average utilization of Benny’s time. (Round your intermediate calculations to 3 decimal places and final answer to 1 decimal place.)
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
A crew of mechanics at the Highway Department Garage repair vehicles that break down at an average of λ = 7.5 vehicles per day (approximately Poisson in nature). The mechanic crew can service an average of μ = 10 vehicles per day with a repair time distribution that approximates an exponential distribution. How much of that time is spent waiting for service?
is queuing theory Five drilling machines at Al Hamriya steel is maintained by Lumina maintenance service with 2 service Engineers. The drilling machines require Maintenance at the of 20 per hour. The engineers fix machine in 2.4 mins every time it goes out of service: 1. What is the probability that no drilling machine needs service ?
Benny the Barber owns a one-chair shop. At barber college, they told Benny that his customers would exhibit a Poisson arrival distribution and that he would provide an exponential service distribution. His market survey data indicate that customers arrive at a rate of two per hour. It will take Benny an average of 20 minutes to give a haircut. Based on these figures, find the following: Part (a): The average number of customers waiting. Arrival Time, λ =2 customers per hour Service Time, μ = 20 minute, or 60/20= 3 customer per hour Lq = (2)2 / 3*(3-2) = 1.333 customers Part (b): The average time a customer waits. Wq= 1.333/2=0,665 \~ 0,67 or 40 minutes Part (c): The average time a customer is in the shop. LS = 2/ 3-2 =2 customers. WS = 2/2 = 1 hour Part (d): The average utilization of Benny’s time. P= λ/ μ = 2/3=0,666 percent ~ 0,67 % Benny the Barber (see Question 1) is considering the addition of a second chair. Customers would be selected for a haircut on a FCFS basis from…
One field representative services 5 customers for a computer manufacturer. Customers request assistance at an average (Poisson-distributed) rate of once every 1.5 working days. The field representative can handle an average (Poisson-distributed) of 1.0 call per day. Determine: Use Table 1. a. The expected number of customers waiting. (Round "X" value to 2 decimal places. Round your answer to 3 decimal places.) Expected number of customers waiting b. The average length of time customers must wait from the initial request for service until the service has been completed. (Round your answer to 2 decimal places.) Average length of time days c. The percentage of time the service rep will be idle. (Round your answer to 1 decimal place.) Percentage of Idle time d. By how much would your answer to part a be reduced if a second field rep were added? (Round your answer to 3 decimal places.) Reduced number of customer(s)
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Benny the Barber owns a one-chair shop. At barber college, they told Benny that his customers would exhibit a Poisson arrival distribution and that he would provide an exponential service distribution. His market survey data indicate that customers arrive at a rate of two per hour. It will take Benny an average of 20 minutes to give a haircut. Based on these figures, find the following a The average number of customers waiting b. The average time a customer waits.
1 The cost of waiting is estimated to be about an average of $20 per hour. Each pump cost about $11000 per year for the maintenance fee and investment loan interests. Assuming 365 days a year and 12 hours per day. Determine how many new pumps need to be installed to minimize the expected total cost per hour. If no new pumps need to be installed, answer 0. 60 customers per hour (mean arrival rate) and 15 customers per hour (mean service rate)
A crew of mechanics at the Department of Transportation garage make minor repairs to snowplows during the winter. The snowplows break down at an average rate of 5 vehicles per day and breakdowns are distributed according to the Poisson distribution. The mechanic can service an average of 8 vehicles per day with a repair time distribution that approximates a negative exponential distribution. Assume an 8 hour day. What is the expected average number of snowplows in the garage (waiting for repair and being repaired)? 5 1.04 1.67 8
Customers arrive at Rich Dunn's Styling Shop at a rate of 2 per hour, distributed in a Poisson fashion. Service times follow a negative exponential distribution, and Rich can perform an average of 6 haircuts per hour. a) The average number of customers waiting for haircuts = ? enter your response here customers (round your response to two decimal places). b) The average number of customers in the shop = ?customers (round your response to two decimal places). c) The average time a customer waits until it is his or her turn = ? enter your response here minutes (round your response to two decimal places).
Ali Baba‘s Car Wash Service Centre is open 6 days a week, but its busiest day isalways on Sunday. From the previous data, Ali Baba estimates that dirty carsarrive at the rate of one every two minutes. One car at a time is cleaned in thisexample of a single-channel waiting line. Assuming Poisson arrivals andexponential service times, find the following: a) Compute the average number of cars in line.