Exam 18: Management of Waiting Lines

Consider these data regarding the multiple-server, priority service queuing model: Priority Average Arrival Rate High 3 per hour (Poisson) Low 5 per hour (Poisson) Service Rate: 2 per hour (Poisson) Number of Servers: 5 What is the average time in line for a low priority item?

If a firm has reached the point at which further reducing waiting time is not economically feasible, reducing the ______________ is sometimes attractive.

Customers filter into a record shop at an average of one per minute (Poisson) where the service rate is 15 per hour (Poisson). Determine the following: (A) the average number of customers in the system with eight servers (B) the minimum number of servers needed to keep the average time in the system to under six minutes

A ________ is one way of reducing perceived waiting time.

Customers arrive at a video rental desk at the rate of one per minute (Poisson). Each server can handle .40 customers per minute (Poisson). (A) If there are four servers, determine: (1) The average time it takes to rent a video (2) The probability of three or fewer customers in the system (B) What is the minimum number of servers needed to achieve an average time in the system of less than three minutes?

A bank of 10 machines requires regular periodic service. Machine running time and service time are both exponential. Machines run for an average of 44 minutes between service requirements, and service time averages six minutes per machine. What is the average machine downtime with two operators?

Servers and channels are described with many acronyms except:

During the early morning hours, customers arrive at a branch post office at an average rate of 45 per hour (Poisson), while clerks can handle transactions in an average time (exponential) of four minutes each. Find: (A) the average number of customers waiting for service if six clerks are used. (B) the minimum number of clerks needed to keep the average time in the system to under five minutes. (C) If clerk cost is $30 per hour and customer waiting time represents a "cost" of $20 per hour, how many clerks can be justified on a cost basis?

All infinite-source queuing models require the system utilization to be less than 1.0.

In an infinite-source model, the average number being served is equal to the ratio of the arrival rate to the service rate.

In which of these settings would one be least likely to encounter first-come service?

A basic difference between infinite-source and finite-source queuing models is the:

In an infinite-source model, the system utilization is the ratio of the arrival rate to the service capacity.

A department has five semiautomatic pieces of equipment which operate for an average of 79 minutes before they must be reloaded. The reloading operation takes an average of 21 minutes per machine. Assume exponential distributions. What is the minimum number of servers needed to keep the average downtime per cycle to less than 25 minutes?

The point that minimizes total queuing system costs is that point where waiting costs and capacity costs are equal.

A single-server, variable-service-time system is known as an M/D/1 system.

A single-channel queuing system has an average service time of 16 minutes per customer, which is exponentially distributed. The manager is thinking of converting to a system with a constant service time of 16 minutes. The arrival rate will remain the same. The effect will be to:

Which of the following is not generally considered to be a measure of system performance in a queuing analysis?

A single-channel queuing system has an average service time of eight minutes and an average time between arrivals of 10 minutes. The arrival rate is:

Customers arrive at a suburban ticket outlet at the rate of 14 per hour on Monday mornings. This can be described by a Poisson distribution. Selling the tickets and providing general information takes an average of three minutes per customer, and varies exponentially. There is one ticket agent on duty on Mondays. Determine each of the following: (A) system utilization (B) average number in line (C) average time in line (D) average time in the system