Waiting lines occur even in under loaded systems because of variability in service rates and/or arrival rates.
TRUE Variability leads to short-term mismatches that lead to waiting lines.
A system has one service facility that can service 10 customers per hour. The customers arrive at a variable rate, which averages 6 per hour. Since there is excess capacity, no waiting lines will form.
FALSE Even if service times don't vary at all, variability in arrivals could lead to waiting lines.
The goal of waiting line management is to eliminate customer waiting lines.
FALSE The goal of waiting line management is to minimize the total of service costs and waiting costs.
The cost of customer waiting is easy to estimate, the number waiting multiplied by the wait cost per minute.
FALSE The wait cost per minute is very difficult to estimate.
In a theme park like Disney world, reservation systems are a win-lose situation since only those holding reservations are satisfied.
FALSE Others who don't get reservations can also be somewhat satisfied, since at least they didn't have to wait in excessively long lines.
The point that minimizes total queuing system costs is that point where waiting costs and capacity costs are equal.
FALSE The minimum total cost point is usually not at the point at which waiting cost and capacity cost curves intersect.
A multiple channel system assumes that each server will have its own waiting line and line changing is not permitted.
FALSE In many cases there is only one waiting line so line changing isn't an issue.
A dental office with two professionals (one dentist, one hygienist) who work together as a team would be an example of a multiple channel system.
FALSE This would be a multiple phase system.
A Single Server, Variable Service Time is known as an M/D/1 system.
FALSE An M/D/1 system would be a single server, constant service time system.
The most commonly used queuing models assume that the arrival rate can be described by a Poisson distribution.
TRUE Poisson arrivals are assumed in the most commonly used queuing models.
The goal of queuing analysis is to balance the cost of providing a level of service capacity with the possible loss of business due to customers leaving the line or refusing to wait.
FALSE The goal is to balance capacity cost with waiting cost.
According to Little's Law, the number of people in line depends on the time of day that they arrive
FALSE According to Little's Law, for stable systems the average number of customers in line or in the system is equal to the average customer arrival rate multiplied by the average time in line or in the system.
For a system that has a low utilization ratio, decreasing service capacity slightly will have only negligible effect on customer waiting time.
TRUE In lightly utilized systems, slight changes to capacity have little effect on waiting times.
An approach to reducing the variability in processing times might include greater standardization.
TRUE The more service can be standardized, the greater the impact on waiting lines.
The queuing models discussed in the text apply only to "steady state" conditions. Steady state exists only when customers arrive at a steady rate; that is, without any variability.
FALSE Steady state means that the average arrival and service rates are stable.
In an infinite source model, the average number being served is equal to the ratio of the arrival rate to the service rate.
TRUE Divide the arrival rate by the service rate.
In an infinite source model, the average time in line is equal to the average number in line divided by the arrival rate.
TRUE This is the average time spent in the queue.
In an infinite source model, the system utilization is the ratio of the arrival rate to the service capacity.
TRUE This is the way to calculate system utilization.
To reduce the average number waiting in line, it is important to increase utilization.
FALSE Increasing utilization will increase the average number waiting in line.
All infinite source queuing models require the system utilization to be less than 1.0.
TRUE All queuing models must have system utilization to be less than 1.0.
Queue discipline requires a security presence to maintain order.
FALSE Queue discipline is simply the manner in which customers or jobs are selected for processing.
Compared to a single channel a system with exponential service time, a single channel system with a constant service time causes a reduction of 50 percent in the average number waiting in line.
TRUE Reducing service variability has a tremendous impact on waiting time.
Compared to a single channel system with exponential service time, the same system with a constant service time will have an average of one-half the number of customers waiting in the system.
FALSE There will be half as many customers waiting in line, not half as many waiting in the system.
If variation in arrival and service rates can be reduced, waiting lines will be shortened.
TRUE Reducing variability shortens waiting lines.
The finite-source queuing model is appropriate when the potential calling population is relatively large.
FALSE The finite-source model is appropriate when the potential calling population is relatively small.
Balking is when customers grow impatient and leave a line.
FALSE Balking is when customers refuse to enter a line.
In a single-channel system, the utilization is equal to the arrival rate divided by the service rate.
TRUE This is how utilization is calculated in such a system.
The goal of waiting line management is to minimize waiting time.
FALSE The goal is to minimize total cost (capacity plus waiting).
Why is there waiting in an infinite source queuing system?
A. poor scheduling of servers
B. slow service
C. low utilization
D. variability in arrival and service rates
E. multiple phase processing
Variability leads to waiting lines.
D. variability in arrival and service rates
30. The goal of queuing analysis is to minimize:
A. the sum of customer waiting costs and capacity costs
B. the sum of customer waiting time and service time
C. capacity costs
D. customer waiting time
E. idle servers
A. the sum of customer waiting costs and capacity costs
A basic difference between infinite source and finite source queuing models is:
A. the number of servers
B. the average waiting time
C. the arrival distribution
D. size of potential calling population
E. processing rate
D. size of potential calling population
If a manager increases system utilization (assuming no change in the customer arrival rate) what happens to the customer waiting time?
A. It increases exponentially.
B. It increases proportionally.
C. It decreases proportionally.
D. It decreases exponenti
A. It increases exponentially.
A single phase queuing system is one which has a single:
A. channel
B. server
C. customer being served
D. operation
E. waiting line
D. operation
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:
A. 6 per hour
B. 7.5 per hour
C. 8 per hour
D. 10 per hour
E. 12.5 per hour
A. 6 per hour
In a _______ system, customers enter the waiting line, receive service and leave.
A. Fast-track
B. Simulated
C. Queuing
D. Random
E. Non-random
C. Queuing
Which of the following is not generally considered as a measure of system performance in a queuing analysis?
A. the average number waiting in line
B. the average number in the system
C. system utilization
D. the cost of servers plus customer waiting cost
E. average serving time
The total cost curve:
A. Starts at zero and increases as service capacity increases.
B. Begins high and decreases as service capacity increases.
C. Starts high, declines, then increases again.
D. Remains relatively flat regardless of service capacity.
E.
C. Starts high, declines, then increases again.
38. Little's Law states that the number of people in a waiting line is the average customer arrival rate multiplied by the ________.
A. average time in the system
B. average waiting time
C. service time minus the waiting time
D. average number in line
E.
A. average time in the system
39. As the ratio of arrival rate to service rate is increased, which of the following is likely?
A. Customers move through the system in less time because utilization is increased.
B. Customers move through the system more slowly because utilization is in
B. Customers move through the system more slowly because utilization is increased.
40. Servers, channels are described with many acronyms except _________.
A. M/P/S
B. M/M/1
C. M/D/1
D. M/M/S
A. M/P/S
41. A single bay car wash with a Poisson arrival rate and an exponential service time has cars arriving an average of 10 minutes apart, and an average service time of four minutes. The system utilization is:
A. .24
B. .40
C. .67
D. 2.50
E. none of these
B. .40
Divide the arrival rate (6 per hour) by the service rate (15 per hour).
42. A multiple channel queuing system with a Poisson arrival rate and exponential service time has an average arrival rate of 4 customers per hour and an average service time of 18 minutes per customer. The minimum number of servers required to avoid an o
B. 2
If the arrival rate is 4 per hour, with only one server the capacity of the system is less than 4 per hour.
Which one of the following measures of system performance is a key measure with respect to customer satisfaction?
A. average number of customers waiting in line
B. system utilization
C. average number of customer in the calling population
D. probability o
A. average number of customers waiting in line
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
D. decrease the average waiting time
When the waiting cost incurred by customers likely varies, an appropriate queuing model is:
A. single channel, single phase
B. single channel, multiple phase
C. multiple channel, single priority
D. multiple channel, multiple phase
E. multiple channel, mul
E. multiple channel, multiple priority
Customers who incur high waiting costs are given higher priority.
46. A ________ is one way of reducing perceived waiting time.
A. Bonus
B. Gatekeeper
C. Reservation
D. Diversion
E. Number calling system
D. Diversion
Diversions reduce perceived waiting time.
47. An alternative strategy to increase the capacity of a service system is:
A. Reducing the number of arrivals.
B. Increasing variability.
C. Increasing the processing rate.
D. Reducing the number of servers.
E. All of the above are viable options.
C. Increasing the processing rate.
Reducing processing time increases the capacity of the system.
A queuing system has four crews with three members each. The number of "servers" is:
A. 3
B. 4
C. 7
D. 12
E. 1
B. 4
Each crew is a server.
A multiple channel system has customers arriving at an average rate of five per hour and an average service time of forty minutes. The minimum number of servers for this system to be under loaded is:
A. 2
B. 3
C. 4
D. 5
E. none of these
Each server has a
C. 4
Each server has a capacity of 1.5 customers per hour. At least four such servers would be necessary for this demand rate.
If a firm has reached the point at which further reducing waiting time is not economically feasible, reducing the ______________ is sometimes attractive.
A. channels
B. perceived service time
C. capacity underload
D. perceived waiting time
E. system under
D. perceived waiting time
Reducing the perceived waiting time can greatly increase customer satisfaction.
Offering an "early bird" special at a restaurant to reduce waiting times during peak hours is an example of ____________.
A. demand shifting
B. queuing psychology
C. service phasing
D. service standardization
E. outsourcing
A. demand shifting
Demand shifting reduces the load placed on the service system during peak times.
A restaurant that implements a limited menu and a "no substitutions" policy during peak dining hours is practicing _____________ with respect to waiting line management.
A. demand shifting
B. queuing psychology
C. service standardization
D. service phasin
C. service standardization
Standardizing the service helps reduce waiting times.
Which of the following would reduce perceived waiting times most dramatically in a doctor's office?
A. putting all clocks out of sight
B. removing couches
C. having the patient fill out forms
D. implementing a "no-cell-phone" policy
E. keeping expected wa
C. having the patient fill out forms
Having the customer fill out forms while waiting would tend to reduce perceived waiting time.
In a multi-channel system with multiple waiting lines, customers shifting among the waiting lines is an example of __________.
A. departing
B. utilizing
C. abandoning
D. balking
E. jockeying
Shifting among waiting lines is an example of jockeying.
E. jockeying
Shifting among waiting lines is an example of jockeying.