Throughout this book, reference has been made to a number of computer programs that are intended to help the understanding of particular topics. They can be used by the interested reader for his own benefit, or they can be used for computer aided teaching.

All programs have been written for the MS–DOS operating system and require modest resources, so that they should work on many popular personal computers. There are English and Spanish versions. In some cases, there are programs that require graphic screens, but there is always an alternative version without them. Each program is accompanied with a document file to explain its use, and one or more example data-files.

Users interested in acquiring these programs should post two DSDD 5¼″ diskettes with a covering letter explaining the intended use (for the purpose of keeping a record) to the following address:

What follows is a short description of each of the programs referred to in the book. All programs have been written by the author. In many cases they are representations of models proposed or developed by others, and they have been written on the basis of published material. Hence, there might be conceptual differences between these versions and the originals, not always involuntary.

DIAL

This program contains a simplified version of Dial's assignment algorithm, with a fixed number of trips from a given pair of origin and destination nodes.