Exam 5: Network Modeling

An oil company wants to create lube oil, gasoline and diesel fuel at two refineries. There are two sources of crude oil. The following Excel spreadsheet shows this problem. What values would you enter in the Risk Solver Platform (RSP) task pane for the following Excel spreadsheet? Objective Cell: Variables Cells: Constraints Cells:

Decision variables in network flow problems are represented by

Draw the network and solution for the maximal flow problem represented by the following Excel spreadsheet. Units Upper Net Supply/ of Flow From To Bound Nodes Flow Demand 4 1 2 4 1 0 0 8 1 3 8 2 0 0 4 2 4 6 3 0 0 0 2 5 2 4 0 0 4 3 4 4 5 0 0 4 3 5 5 8 4 5 9 12 5 1 999 12 Maximal flow

When might a network flow model for a transportation/assignment problem be preferable to a matrix form for the problem?

The street intersections in a city road network represent

What formula would be entered in cell G18 in this Excel model?

A network flow problem that allows gains or losses along the arcs is called a

Draw the network and indicate how many units are flowing along each arc based on the following Risk Solver Platform (RSP) solution. Units Unit Net Supply/ of Flow From To Cost Nodes Flow Demand 5 1 A 2 20 1 -40 -40 35 1 3 15 2 5 5 0 2 4 30 3 5 5 25 3 C 4 10 4 10 10 5 3 5 25 5 5 5 15 4 6 10 6 F 15 15 0 5 6 30 Total 1150

Clifton Distributing has three plants and four distribution centers. The plants, their supply, the distribution centers, their demands, and the distance between each location is summarized in the following table: Distance Center 1 Center 2 Center 3 Center 4 Supply Plant A 45 60 53 75 500 Plant B 81 27 49 62 700 Plant C 55 40 35 60 650 Demand 350 325 400 375 Draw the balanced transportation network for Clifton's distribution problem.

Consider modeling a warehouse with three in-flow arcs and three outflow arcs. The warehouse node is a transshipment node but has a capacity of 100. How would one modify the network model to avoid adding a side constraint that limits either the sum of in-flows or the sum of the out-flows to 100?

What is the objective function in the following maximal flow problem?

Which property of network flow models guarantees integer solutions?

Which method is preferred for solving fully connected transportation problems?

Which formula should be used to determine the Net Flow values in cell K6 in the following spreadsheet model?

What is missing from transportation problems compared to transshipment problems?

What is the constraint for node 2 in the following shortest path problem?

A company wants to determine the optimal replacement policy for its delivery truck. New trucks cost $30,000. The company does not keep trucks longer than 2 years and has estimated the annual operating costs and trade-in values for trucks during each of the 2 years as: $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Age in years }$ 0-1 1-2 Operating Cost \ 15,000 \ 16,500 Trade-in Value \ 20,000 \ 16,000 Draw the network representation of this problem.

A company needs to ship 100 units from Seattle to Denver at the lowest possible cost. The costs associated with shipping between the cities are: $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\underline{\text { \quad\quad\quad\quad\quad\quad\quad\quad\quad To\quad\quad\quad\quad\quad}}$ From Portland Spokane Salt Lake City Denver Seattle 100 500 600 - Portland - 350 300 - Spokane - - 250 200 Salt Lake City - - - 200 What values would you enter in the Risk Solver Platform (RSP) task pane for the following Excel spreadsheet? Objective Cell: Variables Cells: Constraints Cells:

What is the constraint for node 2 in the following maximal flow problem?

Joe Fix plans the repair schedules each day for the Freeway Airline. Joe has 3 planes in need of repair and 5 repair personnel at his disposal. Each plane requires a single repairperson, except plane 3, which needs 2 personnel. Anyone not assigned to maintaining an airplane works in the maintenance shop for the day (not modeled). Each repairperson has different likes and dislikes regarding the types of repairs they prefer. For each plane, Joe has pulled the expected maintenance and determined the total preference matrix for his repair personnel. The preference matrix is: Plane 1 Plane 2 Plane 3 Repair Person 1 11 9 21 Repair Person 2 17 7 13 Repair Person 3 9 12 17 Repair Person 4 14 8 28 Repair Person 5 12 5 12 Draw the balanced network flow for this assignment problem assuming Joe would like to maximize the total preference in his worker-to-aircraft schedule.