Using WinQSB to solve Linear Programming Models

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Using WinQSB to solve Linear Programming Models
Assume we wish to solve the transship problem
depicted in the following network diagram
First, formulate the model in standard LP form.
All constraints must have variables on the left
side and a constant on the right.
Minimize Z 2x14 4x24 5x34 8x45
9x46 Subject To x14 lt 50
x24 lt 60 x34 lt 40
x45 35
x46 25 x14 x24 x34 2x45 2x46
0
Now you are ready to move to the software. From
the WinQSB software set select Linear and
Integer Programming
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2. Complete all parameters. For the example
problem, the completed parameters will appear as
follows
1. Under the File drop-down menu, select new
problem and this dialog box will appear
3. After selecting OK the Spreadsheet form will
appear on the screen
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2. The column headings reflect our new variable
names
1. Rename the variables. Select Variable Names
under the Edit pull-down menu and type the new
names in the white column.
4. The lowerBound of each variable should be 0
and the UpperBound should by M (short hand for
very large)
3. Enter the objective function (row 1) and the
six constraints (rows C1-C6). The spreadsheet
cells contain the coefficients of each decision
variable in the objective function and each
constraint.
5. For larger models, the spreadsheet format may
be difficult to use. In these cases, switch to
the normal model format in order to type the
constraint set and objective function. Select
Switch to Normal Model Form under the Format
pull-down menu. The input screen changes to the
following
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Normal Model Format
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Dont forget to save the formulation by selecting
Save Problem from the File pull-down.
Solution and post optimality report
You will be best served to use the software on
your own computer system. However, if you use
the lab, note that the labs network may have
trouble printing the solution. You may need to
copy and paste a print screen into a package
(such as Word) to print your complete solution