Introduction

In this chapter we will run through a sample problem from beginning to end in order to demonstrate how to use the package. While not all problems or modules are identical there is enough similarity so that seeing one example will make it very easy to use any module in this software. As we mentioned in the introduction the first instruction is to select a module to begin the work.

In the figure above we display the modules as they are listed when you use the [MODULE] command button on the command bar (as opposed to the MODULE option in the main menu at the top). As you can see there are a total of 26 modules available. They are divided into three groups. The first group is typically relevant to all POM and QM books while the second group typically appears only in POM books and the third group appears only in QM texts.

If you choose the MODULE option from the Main Menu then you get the same 26 modules listed in a single list in alphabetical order.

Creating a new problem

Generally the first menu option that will be chosen is FILE followed by either NEW to create a new data set or OPEN to load a previously saved data set. In the figure below we show the creation screen that is used when a new problem is to be created. Obviously, this is an option which will be chosen very often. The creation screens are similar for all modules but there are slight differences that you will see from module to module.

The top line contains a text box into which the title of the problem can be entered. The default title for all problems is '<untitled>' and this can be deleted simply by pressing the [Backspace] key or starting a new title. If you want to change the title later this can easily be done by using the TABLE, TITLE option from the main menu bar.

For many modules it is necessary to enter the number of rows in the problem. Rows will have different names depending on the module. For example in linear programming rows are 'constraints' while in forecasting rows are 'past periods'. At any rate the number of rows can be chosen with either the scroll bar or the text box. As is usually the case in Windows they are connected. As you move the scroll bar the number in the text box changes and as you change the text the scroll bar moves. In general, the maximum number of rows in any module is 90.

This program has the capability to allow you different options for the default row names. Select one of the five radio (option) buttons in order to indicate which style of default naming should be used. In most modules the row names are not used for computations but you should be careful because in some modules (most notably Project management and MRP) the names might be relevant to the computations. In most modules the row names can be changed by editing the data table.

Many modules require the number of columns. This is given in the same way as the number of rows. This program does not give you a choice of default values for column names. Generally, column names can be changed in the data table.

Some modules such as the one shown will have an extra option box such as for choosing minimize or maximize or selecting whether distances are symmetric or not. Select one of these options. In most cases this option can be changed later on the data screen.

When you are satisfied with your choices click on the [OK] button or press the [Enter/return] key. At this point a blank data screen will appear as given in the figure below. Screens will differ module by module but they will all resemble the screen below.

The Data Screen

The data screen was described briefly in Chapter 1. It has a data table and for many models there is extra data that appear above the data table as shown above.

Entering And Editing Data

After a new data set has been created or an existing data set has been loaded the data can be entered or edited. Every entry is in a row and column position. You navigate through the spreadsheet using the cursor movement keys (or the mouse). These keys function in a regular way with one very useful exception - the [Return/enter] key. This key takes you to the next cell in the table first moving to the right and then moving down. In addition if you use this key to enter the data then after you are done with the last cell the program will automatically solve (saving you the trouble of clicking on the [SOLVE] command button.)

The instruction bar on the screen will contain a brief instruction describing what is to be done. There are essentially three types of cells in the data table.

One type is a regular data cell into which you enter either a name or a number. When entering names and numbers simply type the name or number and when done press the [Enter] key or one of the direction keys or point to another cell. If you type an illegal character then a message box will be displayed indicating so.

A second type is a cell which can not be changed.

A third type is a cell which contains a drop-down box. For example the signs in a linear programming constraint are chosen from this type of box as shown below. To see all of the options press the box with the arrow.

When you are finished entering the data press the [SOLVE] button on the command bar or use [F9] or FILE, SOLVE or the solve button on the right of the toolbar and a solution screen will appear as given below. The original data is in black and the solution is in a color (that you can self).

The Solution Screen

An important thing to notice is that there is more solution information available than the one table displayed. This can be seen by the icons given at the bottom. Double click (Windows 3.1) on these to view the information. Alternatively, notice that the WINDOW option in the main menu is now enabled. (This is not shown here but rather below.) It is always enabled at the first solution display

Now that we have examined how to create and solve a problem we explain all of the options that are available in the Main Menu.

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