Exam 17: Waiting Lines

The exponential distribution is based on the assumption that each service time is ________ of those that preceded it.

A phase represents a single step in providing a service.

The four elements common to all waiting-line situations are a customer population,a waiting line of customers,the service facility,and a priority rule.

Scenario B.6 The Jackson Machine Company has four cutting tools that need to be refurbished after an average of 30 hours,according to an exponential distribution.The single machine that refurbishes the tools needs 15 hours for each tool on the average,with exponential service times. -Use the information in Scenario B.6.What is the probability that there will be no tools in the system?

Instead of having one worker perform all eight steps to process a customer,an operations manager assigns each step to a different worker.In doing so,the operations manager has increased the:

The production rate has been steady at 20 units per hour.The average work-in-process inventory at this station is 15 units.What is the average lead time through this manufacturing station?

Students arrive at a university business library during peak evening hours at a rate of 40 students every half hour.Each student stays an average of two hours.On average,how many students are in the library at any one time?

If the nature of the customer population,constraints on the line,the priority rule,and the service time distribution renders waiting line theory no longer useful,then an operations manager should rely on:

A drive thru car wash can process cars at a rate of one every five minutes.When you arrive with your car,you see one car just leaving the washer and eight cars in line ahead of you.How long can you expect to wait before you will reach the car wash?

In a waiting-line problem,increasing advertising expenditures,increasing the number of promotions,or changing the price of a service is most likely to affect:

With a single-server model,increasing the service rate while holding all other factors constant will:

For what number of theater patrons n is the likelihood about a coin flip that there will be that number or fewer based on Scenario B.1?

Customers arrive at the local grocery store at a steady rate of 40 an hour.Thirty percent of these customers purchase 10 items or less and go to the express line where they enjoy an average checkout time of 5 minutes.Customers that don't meet the express line criterion go to the other checkout line where they spend an average of 10 minutes checking out.How many people are checking out in the express line on average?

Customers are serviced at a rate of six customers per hour according to an exponential distribution.What is the probability that customer service will require fewer than 20 minutes?

The standard assumption in the single-server model is that customers are served according to the earliest due date,i.e. ,which customer needs to be finished first.

Twelve customers arrive at the lunch counter at George's Happy Hog per hour and select the hickory smoked meat du jour along with a side and soda for $5.The server doubles as the cashier and can take and fill an order in three minutes on average.What is the likelihood that there is no one being served and no one in line at the George's Happy Hog if the times can be assumed as exponentially distributed?

A super computer-accessory discount store often has customers who leave the checkout line before being served because of excessive waiting times.The store has a(n):

A(n)________ is a single step in providing a service.

You drive your car into the parking lot of your favorite fast food establishment and get in the line for drive through service.After placing your order into the speaker,you proceed to the first window to pay,and then to the second window to pick up your meal.Since you just studied waiting lines that day in your Operations Management class,you quickly realize as you drive away that this was an example of a ________ channel ________ phase queuing system.

Customer arrival rates vary throughout the day and the priority rules change depending on the customer mix and influence each has over the finances of the firm.Such a situation is best analyzed using simulation rather than one of the queuing formulas.