Deck 27: Modeling with Simulation

Question 1

Simulation models that are based on the generation of random numbers may fail to give the same solution in repeated use to any particular problem.

Answer 1

True

Question 2

Simulation has numerous applications in modern business,but few of these are in the area of operations.

Answer 2

False

Question 3

The seven steps in the use of simulation include all EXCEPT which of the following?

A)Define the problem.
B)Construct a numerical model.
C)Introduce important variables associated with the problem.
D)Find the optimal solution.
E)Run the experiment.

Answer 3

Find the optimal solution.

Question 4

Simulation may be capable of producing a more appropriate answer to a complex problem than can be obtained from a mathematical model.

Question 5

The idea behind simulation is threefold: (1)to imitate a real-world situation mathematically, (2)then to study its properties and operating characteristics,and (3)finally to draw conclusions and make action decisions based on the results of the simulation.

Question 6

Define simulation.

Question 7

________ is the attempt to duplicate the features,appearance,and characteristics of a real system,usually via a computerized model.

Question 8

Which of the following is an idea behind simulation?

A)to imitate a real-world situation mathematically
B)study the properties and operating characteristics
C)draw conclusions and make decisions based on the results
D)both A and B
E)A,B,and C are all ideas behind simulation.

Question 9

Which of the following statements regarding simulation is TRUE?

A)Large-scale simulation models are virtually all handled by computer.
B)Simulation has numerous areas of application in operations.
C)Simulation attempts to duplicate a real system.
D)The process of simulation involves seven steps.
E)All of these are true.

Question 10

Identify five applications of simulation.

Question 11

Virtually all large-scale simulations take place on computers,but small simulations can be conducted by hand.

Question 12

Simulation is the attempt to duplicate the features,appearance,and characteristics of a real system,usually by means of a computerized model.

Question 13

Similar to mathematical and analytical models,simulation is restricted to using the standard probability distributions.

Question 14

One effective use of simulation is to study problems for which the mathematical models of operations management are not realistic enough.

Question 15

State the three-fold idea behind simulation.

Question 16

Simulation allows managers to test the effects of major policy decisions on real-life systems without disturbing the real system.

Question 17

Identify the seven steps involved in using simulation.

Question 18

Simulation provides optimal solutions to problems.

Question 19

Which of the following is TRUE regarding simulation?

A)Small problems can be done by hand.
B)Most simulations are computerized.
C)Real-world complications can be included in simulation models.
D)Simulation is most suitable where standard analytical models are too complex.
E)All of the above are true.

Question 20

Despite the powerful simulation software available today,good simulation models can take a long time to develop.

Question 21

One of the advantages of simulation is that:

A)managers must generate all of the conditions and constraints for solutions that they want to examine.
B)it always generates a more accurate solution than a mathematical solution would.
C)the policy changes may be tried without disturbing the real-life system.
D)model development is less time consuming than for mathematical models.
E)model solutions are transferable to a wide variety of problems.

Question 22

A simulation is "Monte Carlo" when the elements of a system being simulated exhibit chance in their behavior.

Question 23

The effects of OM policies over many months or years can be obtained by computer simulation in a short time.This phenomenon is referred to as ________.

Question 24

Which of the following are advantages of simulation? I.time compression
II."what-if?" questions are possible
III.flexibility
IV.repetitive approach
V.input must be user generated

A)I,III,V
B)I,II,V
C)II,III,IV,V
D)I,II,IV,V
E)I,II,III

Question 25

One of the disadvantages of simulation is that it:

A)does not allow for very complex problem solutions.
B)is not very flexible.
C)may be very time-consuming to develop.
D)is very limited in the type of probability distributions that can be used.
E)interferes with the production system while the program is being run.

Question 26

Random number intervals are based on cumulative probability distributions.

Question 27

Which of the following is NOT a disadvantage of simulation?

A)time compression
B)good simulation models can take a long time to develop
C)repetitive approach
D)all input must be user generated
E)All of these are disadvantages to simulation.

Question 28

Simulation is used for several reasons,including which of the following?

A)Model development is a fast process.
B)The models can usually be solved by hand.
C)The models are usually simple.
D)It can handle large and complex real-world problems.
E)It always generates optimal solutions.

Question 29

Explain what is meant by the concept of "time compression" in simulation modeling.

Question 30

"Time compression" and the ability to pose "what-if?" questions are elements of:

A)setting up a probability distribution for important variables.
B)the disadvantages of simulation.
C)physical simulations but not mathematical simulations.
D)the advantages of simulation.
E)the broad threefold idea of simulation.

Question 31

By starting random number intervals at 01,not 00,the top of each range is the cumulative probability.

Question 32

What are the advantages and disadvantages of simulation models?

Question 33

One of the disadvantages of simulation is that it:

A)does not allow for very complex problem solutions.
B)is not very flexible.
C)is a repetitive approach that may produce different solutions in different runs.
D)is very limited in the type of probability distributions that can be used.
E)interferes with the production systems while the program is being run.

Question 34

The Las Vegas method is a simulation technique that uses random elements when chance exists in their behavior.

Question 35

A simulation model is designed to arrive at a single specific numerical answer to a given problem.

Question 36

Which of the following is TRUE regarding the use of simulation?

A)It is always very easy to build a simulation model.
B)It may interfere with real-world systems.
C)It always yields optimal solutions.
D)It allows time-compression in testing major policy decisions.
E)Few constraints,if any,have to be considered.

Question 37

The effects of operations management policies over many months or years can be obtained by computer simulation in a short time.What is this phenomenon called?

A)time suppression
B)time suspension
C)time compression
D)time inversion
E)time conversion

Question 38

Simulation can use any probability distribution that the user defines.

Question 39

One of the advantages of simulation is that:

A)real-world complications can be included that most OM models cannot permit.
B)it always generates a more accurate solution than a mathematical model does.
C)it is a repetitive approach that may produce different solutions in repeated runs.
D)model development is less time consuming than for mathematical models.
E)model solutions are transferable to a wide variety of problems.

Question 40

One of the disadvantages of simulation is that it:

A)does not allow for very complex problem solutions.
B)produces solutions and inferences that are not usually transferable to other problems.
C)time compression may occur.
D)is very limited in the type of probability distributions that can be used.
E)interferes with the production system while the program is being run.

Question 41

From a portion of a probability distribution,you read that P(demand = 0)is 0.05 and P(demand = 1)is 0.10.The cumulative probability for demand = 1 would be which of the following?

A)0.05
B)0.075
C)0.10
D)0.15
E)0.005

Question 42

The ________ method is a simulation technique that uses random elements when chance exists in their behavior.

Question 43

A distribution of service times at a waiting line indicates that service takes 12 minutes 30 percent of the time and 14 minutes 70 percent of the time.In preparing this distribution for Monte Carlo analysis,the service time 13 minutes would be represented by what random number range?

A)00 through 29
B)01 through 30
C)30 through 99
D)31 through 00
E)None of these;13 minutes is not a possible outcome.

Question 44

Explain how Monte Carlo simulation uses random numbers.

Question 45

From a portion of a probability distribution,you read that P(demand = 1)is 0.05,P(demand = 2)is 0.15,and P(demand = 3)is .20.The cumulative probability for demand = 3 would be which of the following?

A)0.133
B)0.200
C)0.400
D)0.600
E)Cannot be determined from the information given.

Question 46

A distribution of service times at a waiting line indicates that service takes 6 minutes 30 percent of the time,7 minutes 40 percent of the time,8 minutes 20 percent of the time,and 9 minutes 10 percent of the time.In preparing this distribution for Monte Carlo analysis,the service time of 8 minutes would be represented by what random number range?

A)20 through 40
B)21 through 40
C)70 through 90
D)71 through 90
E)01 through 20

Question 47

A distribution of service times at a waiting line shows that service takes 6 minutes 30 percent of the time,7 minutes 40 percent of the time,8 minutes 20 percent of the time,and 9 minutes 10 percent of the time.This distribution has been prepared for Monte Carlo analysis.The first two random numbers drawn are 53 and 74.The simulated service times are ________ minutes,then ________ minutes.

A)6;7
B)7;7
C)7;8
D)8;9
E)Cannot determine because no service time probability is that large.

Question 48

Setting up a probability distribution,building a cumulative probability distribution,and generating random numbers are:

A)necessary when the underlying probability distribution is normal.
B)three of the five steps in Monte Carlo simulation.
C)elements of physical simulation but not mathematical simulation.
D)the elements of the threefold idea behind simulation.
E)advantages of simulation.

Question 49

The numbers used to represent each possible value or outcome in a computer simulation are referred to as ________.

Question 50

From a portion of a probability distribution,you read that P(demand = 0)is 0.05,P(demand = 1)is 0.10,and P(demand = 2)is 0.20.What are the two-digit random number intervals for this distribution beginning with 01?

A)01 through 05,01 through 10,and 01 through 20
B)00 through 04,05 through 14,and 15 through 34
C)01 through 05,06 through 15,and 16 through 35
D)00 through 04,00 through 09,and 00 through 19
E)01 through 06,07 through 16,and 17 through 36

Question 51

From a portion of a probability distribution,you read that P(demand = 0)is 0.25,and P(demand = 1)is 0.30.What are the random number intervals for this distribution beginning with 01?

A)01 through 25,and 26 through 30
B)01 through 25,and 01 through 30
C)01 through 25,and 26 through 55
D)00 through 25,and 26 through 55
E)00 through 25,and 26 through 30

Question 52

A(n)________ is a series of digits that have been selected by a totally random process.

Question 53

Identify,in order,the five steps required to implement the Monte Carlo simulation technique.

Question 54

The number of tires sold at a car garage varies randomly between 0 and 4 each hour,with equally probability for each possible outcome.What set of random numbers (on the 01-100 scale)would tire sales of 2 be assigned?

A)01 through 20
B)21 through 40
C)41 through 60
D)51 through 75
E)26 through 50

Question 55

A(n)________ is the accumulation of individual probabilities of a distribution.

Question 56

A distribution of lead times in an inventory problem indicates that lead time was 1 day 20 percent of the time,2 days 30 percent of the time,3 days 30 percent of the time,and 4 days 20 percent of the time.This distribution has been prepared for Monte Carlo analysis.The first four random numbers drawn are 06,63,57,and 02.What is the average lead time of this simulation?

A)1.75 days
B)2 days
C)3 days
D)3.5 days
E)8 days

Question 57

What is the Monte Carlo method?

Question 58

Which of the following is NOT a step in running a Monte Carlo simulation?

A)setting up a probability distribution for important variables
B)building a cumulative probability distribution for each variable
C)establishing an interval of random numbers for each variable
D)generating random numbers
E)All of the above are steps in running a Monte Carlo simulation.

Question 59

A distribution of service times at a waiting line indicates that service takes 12 minutes 30 percent of the time and 14 minutes 70 percent of the time.This distribution has been prepared for Monte Carlo analysis.The first four random numbers drawn are 07,60,77,and 49.What is the average service time of this simulation?

A)12 minutes
B)13 minutes
C)13.5 minutes
D)14 minutes
E)54 minutes

Question 60

What is the cumulative probability of selling 4 tires?

A)1
B).5
C)10
D).2
E).25

Question 61

Complete the following table in preparation for a Monte Carlo simulation.

Question 62

Provide a small example illustrating how random numbers are used in Monte Carlo simulation.

Question 63

Which of the following is a necessity for common EOQ methodology but not simulations?

A)constant lead time
B)variable demand
C)variable holding costs
D)A and B
E)A,B and C

Question 64

Sam's hardware store has an order policy of ordering 12 gallons of a specific primer whenever 7 gallons are on hand (unless there's already an ordered delivery due).The store would like to see how well their policy works.Assume that beginning inventory in period 1 is 10 gallons and that orders are placed at the end of the week to be received one week later.(In other words,if an order is placed at the end of week one,it is available at the beginning of week 3. )Assume that if inventory is not on hand,it will result in a lost sale.The weekly demand distribution obtained from past sales is found in the table below.Also,use the random numbers that are provided and simulate 10 weeks' worth of sales.How many sales are lost?
Random numbers for sales: 37,60,79,21,85,71,48,39,31,35

Question 65

Explain the difference between random numbers and random number intervals.

Question 66

Historical records on a certain product indicate the following behavior for demand.The data represent the 288 days that the business was open during 2000.Convert these data into random number intervals.(Round each probability used to 2 decimal places,e.g. ,0.36)

Question 67

In most real-world inventory problems,lead time and demand vary in ways that make simulation a necessity because mathematical modeling is extremely difficult.

Question 68

Suppose the following random numbers (1,34,22,78,56,98,00,82)were selected during a Monte Carlo simulation that was based on the chart below.What was the average demand per period for the simulation? What is the expected demand?

Question 69

Julie's Diamond Boutique is very concerned with its order policies related to one-carat diamond solitaires.Their current policy is to order 10 diamonds whenever their inventory reaches 6 diamonds (unless there is already an ordered delivery due).Currently there are 8 diamonds on hand.Orders are placed at the end of the month and take one month to arrive .The following distribution of monthly sales has been developed using historical sales.If Julie's Diamond Boutique does not have a diamond on hand,it will result in a lost sale.Use the following random numbers to determine the number of lost sales of one-carat solitaires at the store over 12 months.
Random numbers for sales: 10,24,03,32,23,59,95,34,34,51,08,48

Question 70

Complete the following table in preparation for a Monte Carlo simulation.

Question 71

One reason for using simulation rather than an analytical model in an inventory problem is that the simulation is able to handle probabilistic demand and lead times.

Question 72

Explain what is meant by the statement: "simulation is not limited to using the standard probability distributions."

Question 73

A warehouse manager needs to simulate the demand placed on a product that does not fit standard models.The concept being measured is "demand during lead time," where both lead time and daily demand are variable.The historical record for this product suggests the following probability distribution.Convert this distribution into random number intervals.

Question 74

Complete the following table in preparation for a Monte Carlo simulation.The expected demand is 3.52.

Question 75

Results of simulation experiments with large numbers of trials or long experimental runs will generally be better than those with fewer trials or shorter experimental runs.