Question 1

It is useful to model network problems by listing all of the arcs and their corresponding flows in one long, comprehensive list.

Accepted Answer

A) True 
 B)False  True

Question 2

Exhibit 5-1Sinclair Plastics operates two chemical plants which produce polyethylene; the Ohio Valley plant which can produce up to 10,000 tons per month and the Lakeview plant which can produce up to 7,000 tons per month. Sinclair sells its polyethylene to three different auto manufacturing plants, Grand Rapids (demand = 3000 tons per month), Blue Ridge (demand = 5000 tons per month), and Sunset (demand = 4000 tons per month). The costs of shipping between the respective plants is shown in the table below:
  
-Refer to Exhibit 5-1. Implement the LP model in Solver and obtain the optimal shipping plan. What is the optimized cost?

Accepted Answer

The optimized model below shows the shipping plan, which results in a total cost of $650,000.

Question 3

Exhibit 5-3Steve the auto parts salesman is trying to navigate his way between the rural west Texas towns of Jonestown and Upland. The possible routes for this trip are shown below, along with the mileage along each route.
   $$\begin{array} { l l c c } 
\text { Origin } & & \text { Destination } & \text { Distance (miles) } \
\text { Jonestown } & \text { to } & \text { Haleyville } & 25 \
\text { Jonestown } & \text { to } & \text { Krickburg } & 55 \
\text { Jonestown } & \text { to } & \text { Karn City } & 35 \
\text { Haleyville } & \text { to } & \text { Mart } & 50 \
\text { Haleyville } & \text { to } & \text { Krickburg } & 25 \
\text { Haleyville } & \text { to } & \text { Karn City } & 30 \
\text { Karn City } & \text { to } & \text { Mart } & 50 \
\text { Karn City } & \text { to } & \text { Baker } & 65 \
\text { Krickburg } & \text { to } & \text { Karn City } & 20 \
\text { Krickburg } & \text { to } & \text { Baker } & 30 \
\text { Krickburg } & \text { to } & \text { Mart } & 45 \
\text { Mart } & \text { to } & \text { Baker } & 20 \
\text { Mart } & \text { to } & \text { Upland } & 40 \
\text { Baker } & \text { to } & \text { Upland } & 30
\end{array}$$
-Refer to Exhibit 5-3. Suppose the roads leading into and out of Krickburg are unpaved, so Steve would only be able to travel half of his usual 60 mile/hour speed on those routes. Modify the model to account for this condition. Would the shortest path change from the base case solution?

Accepted Answer

The revised shortest path (in minutes) is shown below. Steve will now travel 115 miles (i.e., 115 minutes @ 60 miles per hour) and Krickburg is no longer on his route.

Question 4

Exhibit 5-3Steve the auto parts salesman is trying to navigate his way between the rural west Texas towns of Jonestown and Upland. The possible routes for this trip are shown below, along with the mileage along each route.
   $$\begin{array} { l l c c } 
\text { Origin } & & \text { Destination } & \text { Distance (miles) } \
\text { Jonestown } & \text { to } & \text { Haleyville } & 25 \
\text { Jonestown } & \text { to } & \text { Krickburg } & 55 \
\text { Jonestown } & \text { to } & \text { Karn City } & 35 \
\text { Haleyville } & \text { to } & \text { Mart } & 50 \
\text { Haleyville } & \text { to } & \text { Krickburg } & 25 \
\text { Haleyville } & \text { to } & \text { Karn City } & 30 \
\text { Karn City } & \text { to } & \text { Mart } & 50 \
\text { Karn City } & \text { to } & \text { Baker } & 65 \
\text { Krickburg } & \text { to } & \text { Karn City } & 20 \
\text { Krickburg } & \text { to } & \text { Baker } & 30 \
\text { Krickburg } & \text { to } & \text { Mart } & 45 \
\text { Mart } & \text { to } & \text { Baker } & 20 \
\text { Mart } & \text { to } & \text { Upland } & 40 \
\text { Baker } & \text { to } & \text { Upland } & 30
\end{array}$$
-Refer to Exhibit 5-3. What general type of LP model can be applied to this problem? What modifications to the general type are required for this problem?

Accepted Answer

The problem can be formulated

Question 5

Exhibit 5-1Sinclair Plastics operates two chemical plants which produce polyethylene; the Ohio Valley plant which can produce up to 10,000 tons per month and the Lakeview plant which can produce up to 7,000 tons per month. Sinclair sells its polyethylene to three different auto manufacturing plants, Grand Rapids (demand = 3000 tons per month), Blue Ridge (demand = 5000 tons per month), and Sunset (demand = 4000 tons per month). The costs of shipping between the respective plants is shown in the table below:
  
-Refer to Exhibit 5-1. Formulate (write out algebraically) an LP transportation model to help Sinclair minimize its shipping costs.

Accepted Answer

Let the decision var

Question 6

Exhibit 5-3Steve the auto parts salesman is trying to navigate his way between the rural west Texas towns of Jonestown and Upland. The possible routes for this trip are shown below, along with the mileage along each route.
   $$\begin{array} { l l c c } 
\text { Origin } & & \text { Destination } & \text { Distance (miles) } \
\text { Jonestown } & \text { to } & \text { Haleyville } & 25 \
\text { Jonestown } & \text { to } & \text { Krickburg } & 55 \
\text { Jonestown } & \text { to } & \text { Karn City } & 35 \
\text { Haleyville } & \text { to } & \text { Mart } & 50 \
\text { Haleyville } & \text { to } & \text { Krickburg } & 25 \
\text { Haleyville } & \text { to } & \text { Karn City } & 30 \
\text { Karn City } & \text { to } & \text { Mart } & 50 \
\text { Karn City } & \text { to } & \text { Baker } & 65 \
\text { Krickburg } & \text { to } & \text { Karn City } & 20 \
\text { Krickburg } & \text { to } & \text { Baker } & 30 \
\text { Krickburg } & \text { to } & \text { Mart } & 45 \
\text { Mart } & \text { to } & \text { Baker } & 20 \
\text { Mart } & \text { to } & \text { Upland } & 40 \
\text { Baker } & \text { to } & \text { Upland } & 30
\end{array}$$
-Refer to Exhibit 5-3. Implement the appropriate model in Solver and determine the shortest path for Steve. How many total miles will he travel on his trip?

Accepted Answer

The optimized shortest path mo

Question 7

The decision variables in transportation problems are:

Accepted Answer

A) profits 
B) costs 
C) flows 
D) capacities 
A) profits 
B) costs 
C) flows 
D) capacities

Question 8

Exhibit 5-2A small engineering firm employs one civil engineer, two engineering technicians, and one summer intern. The types of projects the firm does includes surveys (typically 7 per month), designs (5 per month), and construction project plans (four per month). The times, in hours, required for each employee to complete teach type of project are shown below. Based on their capabilities and time spent on travel and administrative tasks, the engineer, tech 1, tech 2, and intern can handle 5, 4, 4, and 3 projects per month, respectively.
  
-Refer to Exhibit 5-2. Based on their salaries, the engineer, tech 1, tech 2, and intern earn $90, $65, $65, and $45 per hourly, respectively. Change the firm's objective function to minimize staff costs and find the optimal assignment plan. Does it change from the base case?

Accepted Answer

The assignment plan may change

Question 9

Exhibit 5-1Sinclair Plastics operates two chemical plants which produce polyethylene; the Ohio Valley plant which can produce up to 10,000 tons per month and the Lakeview plant which can produce up to 7,000 tons per month. Sinclair sells its polyethylene to three different auto manufacturing plants, Grand Rapids (demand = 3000 tons per month), Blue Ridge (demand = 5000 tons per month), and Sunset (demand = 4000 tons per month). The costs of shipping between the respective plants is shown in the table below:
  
-Refer to Exhibit 5-1. Suppose the shipping capacity between any two plants was limited to 2500 tons per month. Design and implement a network flow version of this model in Solver and obtain the optimal shipping plan. How much more would the shipping plan cost Sinclair in that case?

Accepted Answer

The optimized model below show

Question 10

In transportation problems, shipments between supply points or between demand points are possible.

Accepted Answer

A) True 
 B)False

Question 11

In a minimum cost network flow model, the flow balance constraint for each supply node has the form

Accepted Answer

A) Flow in ≥ Flow out + Net supply 
B) Flow out ≥ Flow in + Net demand 
C) Flow in = Flow out 
D) Flow out ≤ Flow in + Net supply 
E)  Flow in ≤ Flow out + Net demand 
A) Flow in ≥ Flow out + Net supply 
B) Flow out ≥ Flow in + Net demand 
C) Flow in = Flow out 
D) Flow out ≤ Flow in + Net supply 
E)  Flow in ≤ Flow out + Net demand

Question 12

In network models of transportation problems, arcs represent the routes for getting a product from one node to another.

Accepted Answer

A) True 
 B)False

Question 13

For all routes with positive flows in an optimized transportation problem, the reduced cost will be:

Accepted Answer

A) zero 
B) how much less shipping costs would have to be for shipments to occur along that route 
C) how much more shipping costs would have to be for shipments to occur along that route 
D) how much the capacity is along that shipping route 
A) zero 
B) how much less shipping costs would have to be for shipments to occur along that route 
C) how much more shipping costs would have to be for shipments to occur along that route 
D) how much the capacity is along that shipping route

Question 14

Problems which deal with the direct distribution of products from supply locations to demand locations are called:

Accepted Answer

A) transportation problems 
B) assignment problems 
C) network problems 
D) transshipment problems 
A) transportation problems 
B) assignment problems 
C) network problems 
D) transshipment problems

Question 15

Which of the following is not an example of a condition that a more complex logistics model might include?

Accepted Answer

A) Multiple products 
B) Multiple modes of transportation 
C) Multiple time periods 
D) Multiple objectives 
A) Multiple products 
B) Multiple modes of transportation 
C) Multiple time periods 
D) Multiple objectives

Question 16

A particularly useful Excel function in the formulation of transportation problems is the:

Accepted Answer

A) IF function 
B) SUMIF function 
C) SUMPRODUCT function 
D) NPV function 
A) IF function 
B) SUMIF function 
C) SUMPRODUCT function 
D) NPV function

Question 17

The network model representation of the transportation problem has the following advantage relative to the special case of a simple transportation model:

Accepted Answer

A) it does not require capacity restrictions on the arcs of the network 
B) the flows in the network model don't all necessarily have to be from supply locations to demand locations 
C) a network model representation is generally easier to formulate and solve 
D) All of these options 
A) it does not require capacity restrictions on the arcs of the network 
B) the flows in the network model don't all necessarily have to be from supply locations to demand locations 
C) a network model representation is generally easier to formulate and solve 
D) All of these options

Question 18

The flow balance constraint for each transshipment node in a network flow model has the form Flow in = Flow out.

Accepted Answer

A) True 
 B)False

Question 19

In an assignment model of machines to jobs, the machines are analogous to which of the following in a transportation problem?

Accepted Answer

A) Suppliers 
B) Customers 
C) Flows 
D) Unit capacities 
A) Suppliers 
B) Customers 
C) Flows 
D) Unit capacities

Question 20

Transshipment points are locations where goods neither originate nor end up, but goods are allowed to enter such points to be shipped out to their eventual destinations.

Accepted Answer

A) True 
 B)False

It is useful to model network problems by listing all of the arcs and their corresponding flows in one long, comprehensive list.

The decision variables in transportation problems are:

In transportation problems, shipments between supply points or between demand points are possible.

In a minimum cost network flow model, the flow balance constraint for each supply node has the form

In network models of transportation problems, arcs represent the routes for getting a product from one node to another.

For all routes with positive flows in an optimized transportation problem, the reduced cost will be:

Problems which deal with the direct distribution of products from supply locations to demand locations are called:

Which of the following is not an example of a condition that a more complex logistics model might include?

A particularly useful Excel function in the formulation of transportation problems is the:

The network model representation of the transportation problem has the following advantage relative to the special case of a simple transportation model:

The flow balance constraint for each transshipment node in a network flow model has the form Flow in = Flow out.

In an assignment model of machines to jobs, the machines are analogous to which of the following in a transportation problem?

Transshipment points are locations where goods neither originate nor end up, but goods are allowed to enter such points to be shipped out to their eventual destinations.

Introduction to Modeling

Introduction to Spreadsheet Modeling

Introduction to Optimization Modeling

Linear Programming Models

Optimization Models With Integer Variables

Nonlinear Optimization Models

Evolutionary Solver: An Alternative Optimization Procedure

Decision Making Under Uncertainty

Introduction to Simulation Modeling

Simulation Models

Inventory and Supply Chain Models

Queuing Models

Regression and Forecasting Models

Filters

Exam 5: Network Models

It is useful to model network problems by listing all of the arcs and their corresponding flows in one long, comprehensive list.

The decision variables in transportation problems are:

In transportation problems, shipments between supply points or between demand points are possible.

In a minimum cost network flow model, the flow balance constraint for each supply node has the form

In network models of transportation problems, arcs represent the routes for getting a product from one node to another.

For all routes with positive flows in an optimized transportation problem, the reduced cost will be:

Problems which deal with the direct distribution of products from supply locations to demand locations are called:

Which of the following is not an example of a condition that a more complex logistics model might include?

A particularly useful Excel function in the formulation of transportation problems is the:

The network model representation of the transportation problem has the following advantage relative to the special case of a simple transportation model:

The flow balance constraint for each transshipment node in a network flow model has the form Flow in = Flow out.

In an assignment model of machines to jobs, the machines are analogous to which of the following in a transportation problem?

Transshipment points are locations where goods neither originate nor end up, but goods are allowed to enter such points to be shipped out to their eventual destinations.

Introduction to Modeling

Introduction to Spreadsheet Modeling

Introduction to Optimization Modeling

Linear Programming Models

Optimization Models With Integer Variables

Nonlinear Optimization Models

Evolutionary Solver: An Alternative Optimization Procedure

Decision Making Under Uncertainty

Introduction to Simulation Modeling

Simulation Models

Inventory and Supply Chain Models

Queuing Models

Regression and Forecasting Models

Filters