Before taking the self-test, refer to the learning objectives at the beginning of the chapter, the notes in the margins, and the glossary at the end of the chapter.
Use the key at the back of the book to correct your answers.
Restudy pages that correspond to any questions that you answered incorrectly or material you feel uncertain about.
Most systems use the queue discipline known as the FIFO rule.
True
False
Before using exponential distributions to build queuing models, the quantitative analyst should determine if the service time data fit the distribution.
True
False
In a multichannel, single-phase queuing system, the arrival will pass through at least two different service facilities.
True
False
Which of the following is not an assumption in 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.
A queuing system described as would have
exponential service times.
two queues.
constant service times.
constant arrival rates.
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.
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.
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
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.
In performing a cost analysis of a queuing system, the waiting time cost is sometimes based on the time in the queue and sometimes based on the time in the system. The waiting cost should be based on time in the system for which of the following situations?
waiting in line to ride an amusement park ride
waiting to discuss a medical problem with a doctor
waiting for a picture and an autograph from a rock star
waiting for a computer to be fixed so it can be placed back in service
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
In the standard queuing model, we assume that the queue discipline is .
The service time in the queuing model is assumed to be .
When managers find standard queuing formulas inadequate or the mathematics unsolvable, they often resort to to obtain their solutions .