Question 1

A disadvantage of simulation models is that the structuring is highly dependent on the expertise of the modeler.

Accepted Answer

A) True 
 B)False  True

Question 2

A local legal aid office provides basic legal assistance to walk?in clients. The historical arrival frequency is as shown below:
$$\begin{array} { c c  } 
 \text { Clients Arriving } & \text { Relative } \
 \underline { \text { Per Hour } } &  \underline { \text { Frequency}} \
 1 & 20 \% \
 2 & 30 \% \
 3 & 40 \% \
4 & 10 \% \

\end{array}$$

Service times are characterized by a normal distribution with a mean of 10 minutes and a standard deviation of 4 minutes. They are interested in using simulation to find the total amount of service time for each hour of a six-hour working day. They generated the following random numbers for hours 1?6 respectively: 63, 13, 67, 50, 71, and 25.
a. On a scale of 00?99, what random number range corresponds to 3 clients arriving per hour?
b. What is the number of clients arriving in hour 4?
c. What is the total service time in minutes for hour 1?

Accepted Answer

a. $$\begin{array} { c c } 
\text { Clents Arring } & \text { Random Number } \
 \underline { \text { per how} } & \underline {  \text { Categary }} \
1 & 00 - 19 \
2 & 20 - 49 \
3 & 50 - 89 \
4 & 90 - 99
\end{array}$$ 
b. $\begin{array}{ccc}
\text { Hour } & \text { Random } & \text { Number of } \
\underline{\text { of day} } & \underline{\text { Number } }& \underline{\text { Clients Arriving } }\
1 & 63 & 3 \
2 & 13 & 1 \
3 & 67 & 3 \
4 & 50 & 3 \
5 & 71 & 3 \
6 & 25 & 2
\end{array}$ 
c.Hour 1
Client 1: t = 10 + 1.214) = 14.84
Client 2: t = 10 + -1.314) = 4.76
Client 3: t = 10 + -1.124) = 5.52
Total: hour 1 = 25.12 minutes

Hour 2
Client 1: t = 10 + 1.324) = 15.28
Total: hour 2 = 15.28 minutes

Hour 3
Client 1: t = 10 + .864) = 13.44
Client 2: t = 10 + .314) = 11.24
Client 3: t = 10 + -.774) = 6.92
Total: hour 3 = 31.60 minutes

Hour 4
Client 1: t = 10 + 1.904) = 17.60
Client 2: t = 10 + .404) = 11.60
Client 3: t = 10 + -.114) = 9.56
Total: hour 4 = 38.76 minutes

Hour 5
Client 1: t = 10 + -1.634) = 3.48
Client 2: t = 10 + -.754) = 7.00
Client 3: t = 10 + .924) = 13.68
Total: hour 5 = 24.16 minutes

Hour 6
Client 1: t = 10 + -.814) = 6.76
Client 2: t = 10 + -1.124) = 5.52
Total: hour 6 = 12.28 minutes

Question 3

The Rose Warehouse buys roses each week from Panama. A toll?free long distance call is made on Saturday night, and early Monday morning roses arrive at the airport in a box refrigerated with dry ice. The roses cost $8 a dozen and are sold on a cash-and-carry basis for $28 a dozen. Roses left over at the end of the week are put in a trash collector in an alley behind the store. Past sales rounded to the nearest ten dozen) are as follows:
 $\begin{array}{cc}
\text { Dozens of Roses } & \text { Relative } \
\underline{\text { Demanded }} &\underline{ \text { Frequency }}\
110 & 5 \
120 & 20 \
130 & 25 \
140 & 30 \
150 & 20
\end{array}$
 
The owner of the Rose Warehouse wants to compare two ordering rules for ordering roses: 1) order last week's demand plus 10 dozen extra as (safety stock), (2) order 130 dozen every week. He wants to run an eight-week simulation to compare the average weekly profit for the two rules. Last week's demand was for 110 dozen. He generated the following random numbers for weeks 1?8, respectively: 63, 13, 67, 50, 71, 25, 44, and 00. 
a. What is the random number range corresponding to 130 dozen roses demanded?
b. Using ordering rule 1, what is the profit for week 3?
c. Using ordering rule 2, what is the profit for week 6?
d. What is the average profit over all eight weeks for ordering rule 1?

Accepted Answer

a. $\begin{array}{cc}
\text { Dozens of Roses } & \text { Random Number } \
\underline{\text { Demanded }} & \underline{\text { Category }}\
110 & 00-04 \
120 & 05-24 \
130 & 25-49 \
140 & 50-79 \
150 & 80-99
\end{array}$
 
b. If ordered - demand, then profits = ordered)$28 - $8)
If ordered > demand, then profits = demand)$20 - ordered - demand)$8
 $\begin{array}{c}\begin{array}{ccc|}
&\text { Random }\
\underline{ \text { Week }} &\underline{ \text { Number} } & \underline{\text { Demand }} \
 1 & 63 & 140 \
2 & 13 & 120 \
3 & 67 & 140 \
 4 & 50 & 140 \
 5 & 71 & 140 \
6 & 25 & 130 \
 7 & 44 & 130 \
8 & 00 & 110 \
\end{array}
\begin{array}{cc|}
\underline{\text { Rule } 1}\
\underline{ \text { Ordered }}&\underline{ \text {Profit }}\
120 & \$ 2400 \
150 & 2160 \
130 & 2600 \
150 & 2720 \
150 & 2720 \
150 & 2440 \
140 & 2520 \
140 & 1960
\end{array}
\begin{array}{cc}
\underline{\text { Rule } 2}\
\underline{ \text { Ordered }}&\underline{ \text {Profit }}\
130 & \$ 2600 \
130 & 2320 \
130 & 2600 \
130 & 2600 \
130 & 2600 \
130 & 2600 \
130 & 2600 \
130 & 2040
\end{array}
\end{array}$
 
c. $2600
d. Average profit/week = Rule 1: $2440; Rule 2: $2495

Question 4

There is no single test to prove that a model is 100% valid.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following is not correct regarding next-event simulation models?

Accepted Answer

A) Used more commonly in practice 
B) Basis for most commercial simulation software 
C) Waste computer time 
D) More accurate than fixed-time-increment simulation 
A) Used more commonly in practice 
B) Basis for most commercial simulation software 
C) Waste computer time 
D) More accurate than fixed-time-increment simulation

Question 6

Larry sells sweatshirts at football games. The quantity supplied to him is sometimes less than he ordered. The probability distribution below shows the probability of these shortages.
 $$\begin{array} { c c } 
\underline{\text { Sweatshirts units shart) }} & \underline{\text { Probability }} \
0 & 0.5 \
100 & 0.3 \
200 & 0.2
\end{array}$$ 
Simulate the average number of shortages for 15 consecutive orders, using the following single digit random numbers: 1, 6, 8, 3, 4, 5, 7, 0, 3, 8, 9, 3, 2, 4, 2.

Accepted Answer

The answer of Larry sells sweatshirts at football games. The...

Question 7

The table below shows the frequency of service times for a drive-through window.
 $$\begin{array} { c c } 
\underline{\text { Service Time minutes)} } & \underline{\text { Frequency }} \
1 & 2 \
2 & 6 \
3 & 8 \
4 & 13 \
5 & 13 \
6 & 7 \
7 & 1
\end{array}$$ 
a. If the first category service time of (1 minute) started with random number 00, determine the random numbers for a service time for Category 5, five minutes.
b. Determine the random numbers for a service time of seven minutes if the first category starts at random number 00.

Accepted Answer

a. 58 - 83

Question 8

Given the table below with information on lead-time, followed by a set of six random numbers, determine the average lead-time.
 $$\begin{array} { c c } 
\underline{\text { Lead The days) }} & \underline{text { Frequency }} \
 3 & 20 \% \
4 & 70 \% \
5 & 10 \%
\end{array}$$ 
RANDOM NUMBERS: 90, 52, 54, 47, 56, 95

Accepted Answer

The answer of Given the table below with information on...

Question 9

The queuing model operating characteristics formula only characterizes short-term average results and, in many practical situations, managers are interested in understanding long-term dynamic behaviors of queuing systems

Accepted Answer

A) True 
 B)False

Question 10

A busy municipal golf driving range prepares 300 hotdogs daily. For a variety of reasons, the daily demand for hotdogs varies as follows:
 $$\begin{array} { c c } 
\underline{\text { Demand Units} } & \underline{\text { Probability }} \
150 & 0.15 \
200 & 0.20 \
250 & 0.60 \
300 & 0.05
\end{array}$$ 
a. If the hotdogs sell for $1.50 each and cost $0.80 each, determine the range's profit or loss on hotdogs for day three using the following random numbers: 00, 59, 02, 97, 69, 98, 93, 49, 51, 92.
b. If the hotdogs sell for $1.50 each and cost $0.80 each, determine the range's profit or loss on hotdogs for day eight using the following random numbers: 00, 59, 02, 97, 69, 98, 93, 49, 51, 92.
c. If the hotdogs sell for $1.50 each and cost $0.80 each, determine the average daily demand for hotdogs using the following random numbers: 00, 59, 02, 97, 69, 98, 93, 49, 51, 92.

Accepted Answer

a. -$15.00

Question 11

The Excel function (RAND ) generates random numbers that provide a continuous range of values. Unlike those for two-digit numbers, these values are not limited to probability increments of 0.01.

Accepted Answer

A) True 
 B)False

Question 12

Validation consists of all of the following except

Accepted Answer

A) Developing a model with high face validity 
B) Validating model assumptions 
C) Developing logical flow charts 
D) Validating model output 
A) Developing a model with high face validity 
B) Validating model assumptions 
C) Developing logical flow charts 
D) Validating model output

Question 13

Under what situation would an analytical queuing model be used? When would a simulation model be used?

Accepted Answer

Supplementary Chapter B defined the basi

Question 14

All of the following are verification techniques except

Accepted Answer

A) Developing logical flow charts 
B) Testing the probability distribution used to drive the simulation and behavior of system entities 
C) Breaking the problem into smaller pieces or modules 
D) Codes can be checked by others, not just the programmer 
A) Developing logical flow charts 
B) Testing the probability distribution used to drive the simulation and behavior of system entities 
C) Breaking the problem into smaller pieces or modules 
D) Codes can be checked by others, not just the programmer

Question 15

'Balking' means a customer finds the wait while in line too long and thus leaves the line.

Accepted Answer

A) True 
 B)False

Question 16

A pastry store wants to know how many dozen muffins to bake each day. Every dozen they sell fresh in the shop returns a profit of $5.00. Every dozen they bake but do not sell on the day they are baked is given to a local charity at a loss of $3.00 a dozen. The business is fairly stable in that they never sell less than 50 dozen nor more than 80 dozen muffins. Their sales history, rounded to the nearest ten dozen muffins is as shown:
 $$\begin{array} { c c } 
\text { Dozens of } & \text { Number of Days } \
 \underline{\text { Muffins Sold }} &  \underline{\text { That Mary Sold} } \
 50 & 12 \
60 & 37 \
70 & 45 \
80 & 18
\end{array}$$ They want to run a ten day simulation for production rates of 50, 60, 70, and 80 muffins to determine the profit loss) for each. They generated the following random numbers for days 1?10 respectively: 63, 13, 67, 50, 71, 25, 44, 00, 56, and 68. 
a. What range of random numbers corresponds to 70 muffins sold?
b. What is the profit for day 3 if they make 70 dozen muffins?
c. What is the average daily profit for all ten days) corresponding to 60 dozen muffins made?

Accepted Answer

a. Frequency = 45/12 + 37 + 45 + 18) = .

Question 17

'Face validity' means the programmers agree to the model's logic.

Accepted Answer

A) True 
 B)False

Question 18

In regard to a simulation model for inventory management, all of the following are correct except

Accepted Answer

A) Results in an optimal solution with a large simulation 
B) Many days of simulation run are needed to obtain meaningful results 
C) Lead-time can vary 
D) Assumes that a specific reorder point and order quantity have been selected 
A) Results in an optimal solution with a large simulation 
B) Many days of simulation run are needed to obtain meaningful results 
C) Lead-time can vary 
D) Assumes that a specific reorder point and order quantity have been selected

Question 19

With a fixed-time-increment simulation model, detailed information is lost.

Accepted Answer

A) True 
 B)False

Question 20

If variability of demand were the only source of uncertainty, the order quantity and reorder-point decision could be based on a single-period inventory model.

Accepted Answer

A) True 
 B)False

A disadvantage of simulation models is that the structuring is highly dependent on the expertise of the modeler.

There is no single test to prove that a model is 100% valid.

Which of the following is not correct regarding next-event simulation models?

Given the table below with information on lead-time, followed by a set of six random numbers, determine the average lead-time. 3 20\% 4 70\% 5 10\% RANDOM NUMBERS: 90, 52, 54, 47, 56, 95

The queuing model operating characteristics formula only characterizes short-term average results and, in many practical situations, managers are interested in understanding long-term dynamic behaviors of queuing systems

The Excel function (RAND ) generates random numbers that provide a continuous range of values. Unlike those for two-digit numbers, these values are not limited to probability increments of 0.01.

Validation consists of all of the following except

Under what situation would an analytical queuing model be used? When would a simulation model be used?

All of the following are verification techniques except

'Balking' means a customer finds the wait while in line too long and thus leaves the line.

'Face validity' means the programmers agree to the model's logic.

In regard to a simulation model for inventory management, all of the following are correct except

With a fixed-time-increment simulation model, detailed information is lost.

If variability of demand were the only source of uncertainty, the order quantity and reorder-point decision could be based on a single-period inventory model.

Goods, Services, and Operations Management

Value Chains

Measuring Performance in Operations

Operations Strategy

Technology and Operations Management

Goods and Service Design

Process Selection, Design, and Analysis

Facility and Work Design

Supply Chain Design

Capacity Management

Forecasting and Demand Planning

Managing Inventories

Resource Management

Operations Scheduling and Sequencing

Quality Management

Quality Control and Spc

Lean Operating Systems

Project Management

Work Measurement, Learning Curves, and Standards

Queuing Analysis

Modeling Using Linear Programming

Work Measurement, Learning Curves, and Standards

Filters

Exam 22: Simulation

A disadvantage of simulation models is that the structuring is highly dependent on the expertise of the modeler.

There is no single test to prove that a model is 100% valid.

Which of the following is not correct regarding next-event simulation models?

Given the table below with information on lead-time, followed by a set of six random numbers, determine the average lead-time. 3 20\% 4 70\% 5 10\% RANDOM NUMBERS: 90, 52, 54, 47, 56, 95

The queuing model operating characteristics formula only characterizes short-term average results and, in many practical situations, managers are interested in understanding long-term dynamic behaviors of queuing systems

The Excel function (RAND ) generates random numbers that provide a continuous range of values. Unlike those for two-digit numbers, these values are not limited to probability increments of 0.01.

Validation consists of all of the following except

Under what situation would an analytical queuing model be used? When would a simulation model be used?

All of the following are verification techniques except

'Balking' means a customer finds the wait while in line too long and thus leaves the line.

'Face validity' means the programmers agree to the model's logic.

In regard to a simulation model for inventory management, all of the following are correct except

With a fixed-time-increment simulation model, detailed information is lost.

If variability of demand were the only source of uncertainty, the order quantity and reorder-point decision could be based on a single-period inventory model.

Goods, Services, and Operations Management

Value Chains

Measuring Performance in Operations

Operations Strategy

Technology and Operations Management

Goods and Service Design

Process Selection, Design, and Analysis

Facility and Work Design

Supply Chain Design

Capacity Management

Forecasting and Demand Planning

Managing Inventories

Resource Management

Operations Scheduling and Sequencing

Quality Management

Quality Control and Spc

Lean Operating Systems

Project Management

Work Measurement, Learning Curves, and Standards

Queuing Analysis

Modeling Using Linear Programming

Work Measurement, Learning Curves, and Standards

Filters