Chapter 12 Queuing Theory

Most systems use the queue discipline known as the FIFO rule.

True

False

True

Before using exponential distributions to build queuing models, the quantitative analyst should determine if the service time data fit the distribution.

True

False

True

In a multichannel, single-phase queuing system, the arrival will pass through at least two different service facilities.

True

False

False

Which of the following is not an assumption in

𝑀/𝑀/1 models?

Arrivals come from an infinite or very large population.

Arrivals are Poisson distributed.

Arrivals are treated on a FIFO basis and do not balk or renege.

Service times follow the exponential distribution.

The average arrival rate is faster than the average service rate.

The average arrival rate is faster than the average service rate.

Cars enter the drive-through of a fast-food restaurant to place an order, and then they proceed to pay for the food and pick up the order. This is an example of

a multichannel system.

a multiphase system.

a multiqueue system.

none of the above.

a multiphase system.

The utilization factor for a system is defined as

the mean number of people served divided by the mean number of arrivals per time period.

the average time a customer spends waiting in a queue.

the proportion of the time the service facilities are in use.

the percentage of idle time.

none of the above.

the proportion of the time the service facilities are in use.

Which of the following would not have a FIFO queue discipline?

fast-food restaurant

post office

checkout line at grocery store

emergency room at a hospital

emergency room at a hospital

A company has one computer technician who is responsible for repairs on the company’s 20 computers. As a computer breaks, the technician is called to make the repair. If the repairperson is busy, the machine must wait to be repaired. This is an example of

a multichannel system.

a finite population system.

a constant service rate system.

a multiphase system.

a finite population system.

Customers enter the waiting line at a cafeteria on a first-come, first-served basis. The arrival rate follows a Poisson distribution, and service times follow an exponential distribution. If the average number of arrivals is 6 per minute and the average service rate of a single server is 10 per minute, what is the average number of customers in the system?

0.6

0.9

1.5

0.25

none of the above

1.5

In the standard queuing model, we assume that the queue discipline is .

first-come, first-served

The service time in the 𝑀/𝑀/1

queuing model is assumed to be .

negative exponentially distributed

When managers find standard queuing formulas inadequate or the mathematics unsolvable, they often resort to to obtain their solutions.

simulation