Deck 12: Simulation

Question 1

Varying the values of controllable inputs enables simulation models to identify good operating policies and decisions.

Answer 1

True

Question 2

All values of the computer-generated random numbers are equally likely and are uniformly distributed over the interval from 0 to 1.

Answer 2

True

Question 3

Using simulation to perform risk analysis is like playing out many what-if scenarios by randomly generating values for the probabilistic inputs.

Answer 3

True

Question 4

Trials of a simulation show what would happen when values of the probabilistic input change.

Question 5

A static simulation model is used in situations where the state of the system affects how the system changes or evolves over time.

Question 6

A simulation model provides a convenient experimental laboratory for the real system.

Question 7

Verification is the process of ensuring that the simulation model provides an accurate representation of the real system.

Question 8

Validation determines that the computer procedure is operating as it is intended to operate.

Question 9

One disadvantage of simulation is that it is limited in the variety of probability distributions that can be used in modeling a system.

Question 10

To use Excel to generate a normally distributed random variable,you must know the mean and standard deviation of the distribution and have a random number between 0 and 1.

Question 11

Simulation is a method that uses repeated random sampling of values in order to represent uncertainty in a model that represents a real system and computes the values of model outputs.

Question 12

Simulation is an excellent technique to use when a situation is too complicated to use standard analytical procedures.

Question 13

A discrete-event simulation reviews the status of the system periodically,whether or not an event occurs.

Question 14

Each simulation run provides only a sample of how the real system will operate.

Question 15

Simulation is a trial-and-error approach to problem solving.

Question 16

Computer-generated random numbers are not technically random,because they are generated through the use of mathematical formulas.

Question 17

The following relationship is valid for any waiting line system: the average number in the waiting line is equal to the total waiting time divided by the total time of simulation.

Question 18

Simulation is an optimization technique.

Question 19

The degree of risk is associated with the probability or magnitude of loss.

Question 20

Simulation models that must take into account how the system changes or evolves over time are referred to as dynamic simulation models.

Question 21

The process of determining that the computer procedure that performs the simulation calculations is logically correct is called

A)implementation.
B)validation.
C)verification.
D)repetition.

Question 22

Simulation analysis requires a model foundation of logical formulas that correctly express the relationships between parameters and decisions to generate outputs of interest.

Question 23

Independent trials are those in which the results for one trial have no effect on what happens in subsequent trials.

Question 24

Simulation

A)does not guarantee optimality.
B)is flexible and does not require the assumptions of theoretical models.
C)allows testing of the system without affecting the real system.
D)All of these are correct.

Question 25

Which of the following statements is NOT true about the advantages of simulations?

A)Simulation models are flexible.
B)Simulation models can be used to describe systems without requiring the assumptions that are often required by mathematical models.
C)Generally,the larger the number of random variables a system has,the less likely that a simulation model will provide the most suitable approach for studying the system.
D)Simulation models provide a convenient experimental "laboratory" for a real system.

Question 26

Using simulation models,we are able to explore the sensitivity of various decisions to some of the model's

A)parameters.
B)optimizations.
C)uncontrollable input.
D)None of these are correct.

Question 27

The number of units expected to be sold is uniformly distributed between 300 and 500.If r is a random number between 0 and 1,then the proper expression for sales is

A)200(r).
B)r + 300.
C)300 + 500(r).
D)300 + r(200).

Question 28

A value for probabilistic input from a discrete probability distribution

A)is the value given by the RAND()function.
B)is given by matching the probabilistic input with an interval of random numbers.
C)is between 0 and 1.
D)must be nonnegative.

Question 29

A simulation model in which each trial is used in situations where the state of the system at one point in time does not affect the state of the system at future points in time is called a

A)dynamic simulation model.
B)static simulation model.
C)steady-state simulation model.
D)discrete-event simulation model.

Question 30

A quantity that is difficult to measure with certainty is called a

A)risk analysis.
B)project determinant.
C)probabilistic input.
D)profit/loss process.

Question 31

Simulation models manually generate specific values for the random variables so that the values used reflect what we might observe in practice.

Question 32

Simulation allows the user to specify certain desired results (e.g.,profit or service level values),and then the necessary model parameters and operating policies are determined.

Question 33

When events occur at discrete points in time,

A)a simulation clock is required.
B)the simulation advances to the next event.
C)the model is a discrete-event simulation.
D)All of these are correct.

Question 34

Which of the following statements is true regarding the advantages of using simulations?

A)Its methodology can be used to model and learn about the behavior of complex systems.
B)Simulations do not guarantee an optimal solution.
C)Simulation models can be used to describe systems without requiring the assumptions often required by mathematical models.
D)All of these are correct.

Question 35

Values for the random variables or uncertain variable inputs to a simulation are

A)selected by the decision maker.
B)controlled by the decision maker.
C)randomly generated from the specified probability distributions.
D)calculated by fixed mathematical formulas.

Question 36

In order to verify a simulation model,

A)compare results from several simulation languages.
B)be sure that the procedures for calculations are logically correct.
C)confirm that the model accurately represents the real system.
D)run the model long enough to overcome initial start-up results.

Question 37

If customer 2 has a service time of 1.6,and if customer 3 has an interarrival time of 1.1 and a service time of 2.3,when will customer 3's service be completed?

A)5.0
B)3.9
C)3.4
D)There is not enough information to answer.

Question 38

The word "uniform" in the term "uniform random numbers" means

A)all the numbers have the same number of digits.
B)if one number is,say,10 units above the mean,the next number will be 10 units below the mean.
C)all the numbers are odd or all are even.
D)each number has an equal probability of being drawn.

Question 39

A simulation model uses the mathematical expressions and logical relationships of the

A)real system.
B)computer model.
C)performance measures.
D)estimated inferences.

Question 40

When making a decision in the presence of uncertainty,decision makers should only be interested in the average,or expected,outcome.

Question 41

For the past 50 days,daily sales of laundry detergent in a large grocery store have been recorded (to the nearest 10). ​ ​

Question 42

As the owner of a rent-a-car agency,you have determined the following statistics: The gross profit is $40 per car per day rented.When there is demand for a car but none is available,there is a goodwill loss of $80 and the rental is lost.Each day a car is unused costs you $5 per car.Your firm initially has four cars.

Question 43

Seventy-five percent of calls arriving at a help line can be handled by the person who answers the phone,but the remaining 25% of them will need to be referred to someone else.Assume that every call requires one minute of attention by the person who answers the phone (either to answer the question or to figure out how the referral should be handled).Calls that are referred need an additional amount of time,as given in the table below. Callers are served on a first-come,first-served basis and are put on hold until the line is free.Use random numbers to simulate what happens to 10 callers.(Use the random numbers in order,from left to right,first row first,as you need them.)What percentage of your callers needs to be referred? Of those who had to be referred,what is the average referral time? ​

Question 44

Using the spreadsheet below,give the cell address that would have the formula shown. ​

Question 45

A trial-and-error approach to learning about the range of possible outputs for a model is known as

A)what-if analysis.
B)worst-case scenario analysis.
C)static simulation modeling.
D)base-case scenario.

Question 46

A set of values for the random variables is called a

A)simulation.
B)risk analysis.
C)trial.
D)None of these are correct.

Question 47

Estimates of the financial information for a new product include the following information: ​
Use the random numbers 0.51,0.97,0.58,0.22,and 0.16 to simulate five trials.What is the net profit for each trial?

Question 48

A graphical tool that helps describe the logic of the simulation model is a

A)Gantt chart.
B)histogram.
C)flowchart.
D)stem-and-leaf display.

Question 49

The time required to set up lighting for a portrait studio is uniformly distributed between 12 and 20 minutes.Use the following random numbers to generate the setup time for 10 customers.

Question 50

On a visit to an amusement park,you pass someone who has just ridden a roller coaster and asks you for directions to the First Aid Station.Realizing that traffic at the First Aid Station would be something to study with simulation,you gather some information.Two EMTs staff the station,and patients wait and go to the first one available.People coming there can be divided into two groups: those who need something minor (e.g.,Tylenol,a Band-Aid)or those who need more help.​
Assume those in the first group constitute 25% of the patients and take five minutes to have their problem solved.Those in the second group need an uncertain amount of time,as given by a probability distribution.Develop a flowchart for this simulation problem.

Question 51

Susan Winslow has two alternative routes to travel from her home in Olport to her office in Lewisburg.She can travel on Freeway 5 to Freeway 57 or on Freeway 55 to Freeway 91.The time distributions are as follows: ​
Do a five-day simulation of each of the two combinations of routes using the random numbers below.Based on this simulation,which routes should Susan take if her objective is to minimize her total travel time?

Question 52

The process of generating probabilistic inputs and computing the value of the output is called

A)simulation.
B)verification.
C)validation.
D)implementation.

Question 53

Three airlines compete on the route between New York and Los Angeles.Stanton Marketing has performed an analysis of first class business travelers to determine their airline choice.Stanton has modeled this choice as a Markov process and has determined the following transition probabilities: ​