Deck 16: Simulation

Question 1

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

Answer 1

True

Question 2

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.

Answer 2

True

Question 3

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

Answer 3

True

Question 4

Computer-generated random numbers are normally distributed over the interval from 0 to 1.

Question 5

In a Monte Carlo simulation,each simulation trial is dependent upon the result of a previous trial.

Question 6

For any waiting line system, (Average number of units in waiting line)= (Total waiting time)divided by (Total time of simulation).

Question 7

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

Question 8

Computer-generated random numbers are normally distributed.

Question 9

The parameters of a simulation model are the controllable inputs.

Question 10

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

Question 11

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

Question 12

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

Question 13

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

Question 14

In comparing different policies using simulation,one should use the same set of random numbers whenever possible.

Question 15

Computer-generated random numbers are not technically random.

Question 16

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

Question 17

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

Question 18

Simulation is an optimization technique.

Question 19

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

Question 20

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

Question 21

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 non-negative.

Question 22

Common features of simulations--generating values from probability distributions,maintaining records,recording data and summarizing results--led to the development of

A)Excel and Lotus.
B)BASIC,FORTRAN,PASCAL,and C.
C)GPSS,S

Question 23

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

Question 24

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 25

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 26

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 the alternatives are correct.

Question 27

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 the alternatives are correct.

Question 28

A simulation model 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 29

A table of uniformly distributed random numbers should be read

A)from left to right.
B)from top to bottom.
C)diagonally,starting from the top left corner and moving to the bottom right.
D)in any consistent sequence.

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

Numerical values that appear in the mathematical relationships of a model and are considered known and remain constant over all trials of a simulation are

A)parameters.
B)probabilistic input.
C)controllable input.
D)events.

Question 32

Which of the following statements is INCORRECT regarding the disadvantages of simulation?

A)Each simulation run only provides a sample of how the real system will operate.
B)The summary of the simulation data only provides estimates about the real system.
C)The process of developing a simulation model of a complex system can be time-consuming.
D)The larger the number of probabilistic inputs a system has,the less likely a simulation will provide the best approach for studying the system.

Question 33

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 34

Values for the probabilistic inputs to a simulation

A)are selected by the decision maker.
B)are controlled by the decision maker.
C)are randomly generated based on historical information.
D)are calculated by fixed mathematical formulas.

Question 35

Which of the following statements is INCORRECT regarding the advantages of simulation?

A)Simulation is relatively easy to explain and understand.
B)Simulation guarantees an optimal solution.
C)Simulation models are flexible.
D)A simulation model provides a convenient experimental laboratory for the real system.

Question 36

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 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

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

Question 39

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 40

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

Question 41

​Simulation is to be used to study customer waiting patterns at several branches of an organization.Acknowledging
that arrivals and service times follow different distributions over the branches,of what use is the development of a
general simulation model?

Question 42

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 5 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 43

An airline reservation system first asks customers whether they want to schedule a domestic or an international flight.Sixty-five percent of the reservations are for domestic flights.The time distribution of advance sales is also important,and it is given below.
​

a.Place the appropriate random number ranges in the tables above.
b.Set up and perform a simulation for three customers.Determine whether they want a domestic or international flight,and how far in advance the reservation is being made.Use random numbers from this list: .632 .715 .998 .671 .744 .021

Question 44

Greenfields is a mail order seed and plant business.The size of orders is uniformly distributed over the interval from $25 to $80.Use the following random numbers to generate the size of 10 orders.

Question 45

The process of ensuring that the simulation model provides an accurate representation of a real system is called​

A)​risk analysis
B)​verification
C)​validation
D)​static modeling

Question 46

The drying rate in an industrial process is dependent on many factors and varies according to the following distribution.
​

Question 47

​How can historical information be used to create discrete probability distributions?

Question 48

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

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

Question 49

​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 50

​How are both analysts and managers involved in the validation process?

Question 51

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 52

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

Question 53

Estimates of the financial information for a new product show the following information:
​
Use the random numbers .51,.97,.58,.22,and .16 to simulate five trials.What is the net profit for each trial?

Question 54

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

Question 55

​Why would one want to use a general purpose programming language rather than a spreadsheet to develop a
simulation?

Question 56

​The term Monte Carlo simulation refers to any simulation that involves

A)​what-if analysis
B)​discrete-event modeling
C)​the comparison of worst-case and best-case scenarios
D)​randomly generating values for the probabilistic inputs

Question 57

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 when 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 4 cars.

Question 58

Arrivals to a truck repair facility have an interarrival time that is uniformly distributed between 20 and 50 minutes.Service times are normally distributed with mean 30 minutes and standard deviation 10 minutes.Develop a spreadsheet model to simulate the arrival of 100 trucks.Collect information on the time the repair facility is idle and on the average waiting time for trucks.

Question 59

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 60

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.
​

Question 61

​Why is a flowchart useful in simulation?

Question 62

​Explain the difference between verification and validation as they relate to a simulation model.