Linear Programming Models: Graphical and Computer Methods

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GBA334_Facility_Location_Problem_Using_QM.pdf

Facility Location Problem Using QM In this tutorial, we will solve a facility location problem using linear programming with Excel QM. Don Levine Corporation is considering adding a plant to its existing three facilities in Decatur, Minneapolis, and Carbondale. Both St. Louis and East St. Louis are being considered. Evaluating only the transportation costs in the tables below, which site is best?

To \ From Decatur Minneapolis Carbondale Demand

Blue Earth 20 17 21 250

Ciro 25 27 20 200

Des Moines 22 25 22 350

Capacity 300 200 150

To \ From East St. Louis St. Louis

Blue Earth 29 27

Ciro 30 28

Des Moines 30 31

Capacity 150 150

To make our decision, we need to run a transportation problem twice, once with the information for East St. Louis, and once with the information for St. Louis and see our lowest cost option. Now, let’s open Excel QM and solve our problem. Click on the Excel QM tab  Alphabetical  Transportation.

In the Spreadsheet Initialization window, be sure to identify that we have four origins and three destinations and we want to minimize our costs.

Click OK. A spreadsheet will display.

Enter the data shown above into the spreadsheet table. As noted the first time, we will use the data for East St. Louis.

Once you have the data entered correctly, click the Data tab and then Solver.

A Solver Parameters window will appear.

Click Solve and then OK in the Solver Results window. Our results are shown on the next page.

First Option (East St. Louis):

Data

COSTS Blue Earth Ciro

Des Moines Supply

Decatur 20 25 22 300

Minneapolis 17 27 20 200

Carbondale 21 20 22 150

East St. Louis 29 30 30 150

Demand 250 200 350 800 \ 800

Shipments

Shipments Blue Earth Ciro

Des Moines

Row Total

Decatur 50 0 250 300

Minneapolis 200 0 0 200

Carbondale 0 150 0 150

East St. Louis 0 50 100 150

Column Total 250 200 350

800 \ 800

Total Cost 17400

Click here to download the completed spreadsheet table so you can compare it to yours.

Now, to do the second option with Saint Louis, replace the information for East Saint Louis with that of Saint Louis as shown here.

Once you have the data entered correctly, click the Data tab and then Solver.

A Solver Parameters window will appear.

Click Solve and then OK in the Solver Results window.

Our results are shown here.

Data

COSTS Blue Earth Ciro

Des Moines Supply

Decatur 20 25 22 300

Minneapolis 17 27 20 200

Carbondale 21 20 22 150

St Louis 27 28 31 150

Demand 250 200 350 800 \ 800

Shipments

Shipments Blue Earth Ciro

Des Moines

Row Total

Decatur 0 0 300 300

Minneapolis 150 0 50 200

Carbondale 0 150 0 150

St Louis 100 50 0 150

Column Total 250 200 350

800 \ 800

Total Cost 17250

From the results, we can see the total costs for East St. Louis are $17,400 and from St. Louis is $17,250. Our best option would be to build the St. Louis plant. Click here to download the completed spreadsheet table so you can compare it to yours. This concludes our tutorial on solving facility location linear programming problems using Excel QM.