Deck 14: Simulation Modeling

Question 1

Simulation of a business or process is generally performed by building a mathematical model to represent the process or system.

Answer 1

True

Question 2

When using a random number generator, one should never start in the middle of the table of random numbers.

Answer 2

False

Question 3

Simulation is very flexible. Thus, its solutions and inferences are usually transferable to other problems.

Answer 3

False

Question 4

One of the major advantages of simulation is "time compression," i.e., the ability to study in a relatively short period, activities that would, in reality, take place over a period of days, months, or even years.

Question 5

A major advantage of using simulation techniques is to be able to study the interactive effect of individual components/variables.

Question 6

Simulation models are useful for economic order quantity problems with probabilistic demand and lead time.

Question 7

One disadvantage of simulation is that it does not allow for "what-if?" types of questions.

Question 8

To "simulate" is to try to duplicate the features, appearance, and characteristics of a real system.

Question 9

Monte Carlo simulation was developed as a quantitative technique by the great mathematician John von Neumann during World War I.

Question 10

While it is powerful, simulation is not considered to be a flexible quantitative analysis tool.

Question 11

Simulation models are limited to using standard probability distributions such as Poisson, exponential, normal, etc.

Question 12

The wider the variation among results produced by using different sets of random numbers, the longer we need to run the simulation to obtain reliable results.

Question 13

If we are using a Monte Carlo simulation model, we should expect the model to produce the same results for each set of random numbers used.

Question 14

Simulation models are designed to generate optimal solutions, which can then be applied to real-world situations.

Question 15

Despite the power of simulation, less than 20% of the largest U.S. corporations use simulation in corporate planning.

Question 16

Simulation can use any probability distribution that the user defines; it does not require standard distributions.

Question 17

Simulation models may contain both deterministic and probabilistic variables.

Question 18

The four disadvantages of simulation are cost, its trial-and-error nature, time compression, and uniqueness.

Question 19

The Monte Carlo simulation is used with variables that are probabilistic.

Question 20

A flow diagram is helpful in the logical coding procedures for programming a simulation process.

Question 21

Table 14-3
A pawn shop in Arlington, Texas, has a drive-through window to better serve customers. The following tables provide information about the time between arrivals and the service times required at the window on a particularly busy day of the week. All times are in minutes. The first random number generated for arrivals is used to tell when the first customer arrives after opening.
According to Table 14-3, the time between successive arrivals is 1, 2, 3, or 4 minutes. The store opens at 8:00 a.m., and random numbers are used to generate arrivals and service times. The first random number to generate an arrival is 39, while the first service time is generated by the random number 94. What time would the first customer finish transacting business?

A) 8:03
B) 8:04
C) 8:05
D) 8:06
E) None of the above

Question 22

Operational gaming involves a single player competing with the computer simulated game.

Question 23

There are three categories of simulation models: Monte Carlo, operational gaming, and systems simulation.

Question 24

Table 14-2
A pharmacy is considering hiring another pharmacist to better serve customers. To help analyze this situation, records are kept to determine how many customers will arrive in any 10-minute interval. Based on 100 ten-minute intervals, the following probability distribution has been developed and random numbers assigned to each event.
According to Table 14-2, the number of arrivals in any 10-minute period is between 6 and 10 inclusive. Suppose the next 3 random numbers were 02, 81, and 18. These numbers are used to simulate arrivals into the pharmacy. What would the average number of arrivals per 10-minute period be based on this set of occurrences?

A) 6
B) 7
C) 8
D) 9
E) None of the above

Question 25

Table 14-1
A new young mother has opened a cloth diaper service. She is interested in simulating the number of diapers required for a one-year- old. She hopes to use this data to show the cost effectiveness of cloth diapers. The table below shows the number of diapers demanded daily and the probabilities associated with each level of demand.
According to Table 14-1, if the random number 96 were generated for a particular day, what would the simulated demand be for that day?

A) 5
B) 6
C) 7
D) 8
E) None of the above

Question 26

If, for a simple queuing or waiting line problem, we compare the solution from an analytical model with that from a simulation, we will typically find them to be exactly the same.

Question 27

Table 14-2
A pharmacy is considering hiring another pharmacist to better serve customers. To help analyze this situation, records are kept to determine how many customers will arrive in any 10-minute interval. Based on 100 ten-minute intervals, the following probability distribution has been developed and random numbers assigned to each event.
According to Table 14-2, the number of arrivals in any 10-minute period is between 6 and 10, inclusive. Suppose the next three random numbers were 18, 89, and 67, and these were used to simulate arrivals in the next three 10-minute intervals. How many customers would have arrived during this 30-minute time period?

A) 22
B) 23
C) 24
D) 25
E) None of the above

Question 28

Table 14-1
A new young mother has opened a cloth diaper service. She is interested in simulating the number of diapers required for a one-year- old. She hopes to use this data to show the cost effectiveness of cloth diapers. The table below shows the number of diapers demanded daily and the probabilities associated with each level of demand.
According to Table 14-1, if the random number 40 were generated for a particular day, what would the simulated demand be for that day?

A) 5
B) 6
C) 7
D) 20
E) None of the above

Question 29

The advantage of simulation over queuing or waiting line models is that simulation allows us to relax our assumptions regarding arrival and service distributions.

Question 30

The following is not an advantage of simulation:

A) It allows for the study of what-if questions.
B) Each simulation model is unique.
C) It allows the study of interaction of components or variables to determine which are important.
D) It allows time compression.
E) None of the above

Question 31

When establishing a probability distribution based on historical outcomes, the relative frequency for each possible outcome of a variable is found by dividing the frequency of each outcome by the total number of observations.

Question 32

In assigning random numbers in a Monte Carlo simulation,

A) it is important to develop a cumulative probability distribution.
B) it is important to use a normal distribution for all variables simulated.
C) it is not important to assign probabilities to an exact range of random number intervals.
D) All of the above
E) None of the above

Question 33

If, in a simple queuing or waiting line problem, we wish to know the maximum likely waiting time, or the maximum likely length of the line, we must use a simulation model.

Question 34

Simulation of maintenance problems can help management analyze various staffing strategies based on machine downtime and labor cost.

Question 35

Simulation can be effectively used in many

A) inventory problems.
B) plant layout problems.
C) maintenance policy problems.
D) sales forecasting problems.
E) All of the above

Question 36

Table 14-2
A pharmacy is considering hiring another pharmacist to better serve customers. To help analyze this situation, records are kept to determine how many customers will arrive in any 10-minute interval. Based on 100 ten-minute intervals, the following probability distribution has been developed and random numbers assigned to each event.
According to Table 14-2, the number of arrivals in any 10-minute period is between 6 and 10, inclusive. Suppose the next three random numbers were 20, 50, and 79, and these were used to simulate arrivals in the next three 10-minute intervals. How many customers would have arrived during this 30-minute time period?

A) 18
B) 19
C) 20
D) 21
E) None of the above

Question 37

Validation relates to building the right model.

Question 38

Monte Carlo simulation was developed by ________.

A) John von Neumann
B) Eric von Brock
C) A.K. Erlang
D) P.K. Poisson
E) J.D. Monte Carlo

Question 39

Table 14-3
A pawn shop in Arlington, Texas, has a drive-through window to better serve customers. The following tables provide information about the time between arrivals and the service times required at the window on a particularly busy day of the week. All times are in minutes. The first random number generated for arrivals is used to tell when the first customer arrives after opening.
According to Table 14-3, the time between successive arrivals is 1, 2, 3, or 4 minutes. If the store opens at 8:00 a.m., and random numbers are used to generate arrivals, what time would the first customer arrive if the first random number were 02?

A) 8:01
B) 8:02
C) 8:03
D) 8:04
E) None of the above

Question 40

Table 14-1
A new young mother has opened a cloth diaper service. She is interested in simulating the number of diapers required for a one-year- old. She hopes to use this data to show the cost effectiveness of cloth diapers. The table below shows the number of diapers demanded daily and the probabilities associated with each level of demand.
According to Table 14-1, what is the cumulative probability that demand is less than or equal to 7?

A) 0.85
B) 0.95
C) 0.80
D) 0.15
E) None of the above

Question 41

Consider the interval of random numbers presented below. The following random numbers have been generated: 99, 98, 26, 09, 49, 52, 33, 89, 21, 37. Simulate 10 hours of arrivals at this gas station. What is the average number of arrivals during this period?

Question 42

The process of comparing a model to the real system that it represents to make sure it is accurate is called

A) validation.
B) verification.
C) simulation.
D) experimentation.
E) None of the above

Question 43

The logic in a simulation model is presented graphically through which of the following?

A) scatterplot
B) flowchart
C) blueprint
D) decision tree
E) None of the above

Question 44

Customer arrivals adhere to the following probability distribution: Create an appropriate table of interval of random numbers.

Question 45

A certain grocery store has created the following tables of intervals of random numbers with regard to the number of people who arrive at its three checkout stands ready to check out, and the time it takes to check out the individuals. Simulate the utilization rate of the three checkout stands over four minutes using the following random numbers for arrivals: 07, 60, 49, and 95. Use the following random numbers for service: 77, 76, 51, and 16. Describe the results at the end of the four-minute period.

Question 46

Table 14-4
According to Table 14-4, which presents a summary of the Monte Carlo output from a simulation of 200 runs, there are 5 possible values for the variable of concern. If this variable represents the number of machine breakdowns during a day, what is the probability that the number of breakdowns is 2 or fewer?

A) 0.23
B) 0.31
C) 0.32
D) 0.63
E) None of the above

Question 47

The time between arrivals at a drive-through window of a fast-food restaurant follows the distribution given below. The service time distribution is also given in the table below. Use the random numbers provided to simulate the activity of the first five arrivals. Assume that the window opens at 11:00 a.m. and the first arrival after this is based on the first interarrival time generated. Random numbers for arrivals: 14, 74, 27, 03
Random numbers for service times: 88, 32, 36, 24
What times does the fourth customer leave the system?

Question 48

The number of machine breakdowns in a day is 0, 1, or 2, with probabilities 0.6, 0.3, and 0.1, respectively. The following random numbers have been generated: 13, 10, 02, 18, 31, 19, 32, 85, 31, 94. Use these numbers to generate the number of breakdowns for 10 consecutive days. What proportion of these days had at least one breakdown?

Question 49

Table 14-3
A pawn shop in Arlington, Texas, has a drive-through window to better serve customers. The following tables provide information about the time between arrivals and the service times required at the window on a particularly busy day of the week. All times are in minutes. The first random number generated for arrivals is used to tell when the first customer arrives after opening.
According to Table 14-3, the time between successive arrivals is 1, 2, 3, or 4 minutes. The store opens at 8:00 a.m., and random numbers are used to generate arrivals and service times. The first two random numbers for arrivals are 95 and 08. The first two random numbers for service times are 92 and 18. At what time does the second customer finish transacting business?

A) 8:07
B) 8:08
C) 8:09
D) 8:10
E) None of the above

Question 50

Table 14-4
According to Table 14-4, which presents a summary of the Monte Carlo output from a simulation of 200 runs, there are 5 possible values for the variable of concern. If this variable represents the number of machine breakdowns during a day, what is the probability that the number of breakdowns is more than 4?

A) 0
B) 0.08
C) 0.09
D) 1.00
E) None of the above

Question 51

Which of the following is not considered one of the 5 steps of Monte Carlo Simulation?

A) establishing probability distributions for important input variables
B) generating random number
C) building a cumulative probability distribution for each input variable
D) establishing an objective function
E) simulating a series of trials

Question 52

The number of cars arriving at a self-service gasoline station during the last 50 hours of operation are as follows: Create an appropriate table of interval of random numbers.

Question 53

A certain grocery store has noted the following figures with regard to the number of people who arrive at its three checkout stands ready to check out, and the time it takes to check out the individuals. Create an appropriate table of interval of random numbers for both variables.

Question 54

Which of the following scenarios would require simulation for a queuing model?

A) Poisson arrival process
B) exponential service time
C) deterministic arrival process
D) deterministic service time
E) None of the above

Question 55

Table 14-3
A pawn shop in Arlington, Texas, has a drive-through window to better serve customers. The following tables provide information about the time between arrivals and the service times required at the window on a particularly busy day of the week. All times are in minutes. The first random number generated for arrivals is used to tell when the first customer arrives after opening.
According to Table 14-3, the time between successive arrivals is 1, 2, 3, or 4 minutes. The store opens at 8:00 a.m., and random numbers are used to generate arrivals and service times. The first 3 random numbers to generate arrivals are 09, 89, and 26. What time does the third customer arrive?

A) 8:07
B) 8:08
C) 8:09
D) 8:10
E) None of the above

Question 56

The use of simulations in competitive situations is called

A) Monte Carlo simulation.
B) systems simulation.
C) operational gaming.
D) virtual reality.
E) None of the above

Question 57

Table 14-4
According to Table 14-4, which presents a summary of the Monte Carlo output from a simulation of 200 runs, there are 5 possible values for the variable of concern. If random numbers between 01 and 100 are used to generate values, then a random draw of 72 would produce a variable value of ________.

A) 0
B) 1
C) 2
D) 3
E) 4

Question 58

Simulation models can be broken down into which of the following three categories?

A) Monte Carlo, queuing, and inventory
B) queuing, inventory, and maintenance policy
C) Monte Carlo, operational gaming, systems simulation
D) inventory, systems simulation, and operational gaming
E) None of the above

Question 59

The process of determining that the computer model is internally consistent and following the logic of the conceptual model is called

A) validation.
B) verification.
C) simulation.
D) experimentation.
E) None of the above

Question 60

Which of the following represents the primary reason simulation cannot be used for the classic EOQ model?

A) too many parameters involved
B) too many decision variables
C) EOQ models are probabilistic
D) EOQ models are deterministic
E) None of the above

Question 61

A local computer store is running a sale on the first 99 flat panel monitors sold. There is an equally likely chance of 0-99 units being sold. Each monitor cost $250, and profit is $10 per monitor sold. That is, profit equals -$250 + $10X, where X = the number of monitors sold. The mean amount you would expect to sell is 49.5 units.
(a) Calculate the expected profit.
(b) Simulate the sale of 10 items, using the following double digit random numbers: 47, 77, 98, 11, 02, 18, 31, 20, 32, 90.
(c) Calculate the average profit in (b) above, and compare with the results of (a) above.

Question 62

List the major advantages of simulation techniques.

Question 63

A computer help desk receives new daily customer arrivals according to the following probability distribution: The number of customers that the help desk has the capability to serve per day is based on the following probability distribution: If the number of arrivals exceeds the # served capability, the customers will receive top priority the next day. The random numbers drawn for a 5-day simulation are as follows: What will the average number of delays be for the 5 day simulation?

Question 64

List the major disadvantages of simulation techniques.

Question 65

Explain what is meant by operational gaming and give one example.

Question 66

Explain what is meant by a Monte Carlo simulation.

Question 67

The demand for refrigerators at an appliance store adheres to the following probability distribution: The store orders 4 refrigerators per day to have in stock to meet demand. They are trying to maintain low inventory levels. The holding cost is $5/unit/day. The ordering cost is $20 per order. The lost sale cost is $10/unit. A simulation is to be developed to estimate the average daily inventory cost over 5 days. The table below shows the random numbers to be used for refrigerator demand and lead time on orders: Assuming that beginning inventory is equal to 5 with no prior orders in transit, what is the overall average daily cost of inventory for the 5 days?

Question 68

What are the seven steps of simulation?