The document provides instructions for using WinQSB software to solve a linear programming transshipment problem. It describes how to: 1) Formulate the transshipment problem as a linear program with an objective function and constraints 2) Enter the model into the WinQSB software by defining the variables, objective function, and constraints either using a spreadsheet format or normal model format 3) Solve the linear program using the software and save/print the optimal solution.

1. 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 50 1 2
LP form. All constraints must have 8 5 35
variables on the left side and a constant 4
60 2 4 9
on the right.
5 6 25
40 3
Minimize Z= 2x14 + 4x24 + 5x34 + 8x45 + 9x46 From the transshipment node: 1 unit of
output requires 2 units of input
Subject To: x14 <= 50
x24 <= 60
Now you are ready to
x34 <= 40 move to the software.
x45 = 35 From the WinQSB
software set select “Linear
x46 = 25
and Integer Programming”
x14 + x24 + x34 – 2x45 – 2x46 = 0

2. 2. Complete all
1. Under the parameters. For the
File drop-down example problem,
menu, select the completed
“new problem” parameters will
and this dialog
appear as follows
box will appear
3. After selecting OK the
Spreadsheet form will
appear on the screen

3. 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 4. The lowerBound
column. 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:

4. Normal Model Format
To solve the formulation select “solve the
problem” under the “Solve and Analyze” pull-
down. Alternatively, select the running man icon

5. Don’t forget to save
Solution and post the formulation by
optimality report selecting “Save
Problem” from the
“File” pull-down.
You will be best served to use the software on your own computer system.
However, if you use the lab, note that the lab’s 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