Use of Computer Systems in Linear Programming

When a computer is to be used for linear programming there are a number of steps:

(1) Development of the equations which describe the system;

(2) Set up the matrix and some packages include a matrix generator which allows the data to be specified in a form suitable for the use with the package, converting it to the form required for the application of the mathematical techniques. The input program should include routines for checking the data and provide comprehensive and understandable error messages.

(3) Production of the solution; some packages can run in either batch or interactive mode, the former being more appropriate with large problems where the time required to reach a solution is fairly long. Since the size of the matrix grows rapidly as the number of constraints and variables increases, potential users need to investigate that the limitations imposed by the package and the hardware on which it runs are not such as to restrict their problem formulation.

(4) Output of the results in a form suitable for the user; again many packages include a report writer. Users may require the facility to examine the results and possibly modify some of the constraints prior to selecting a set of printed reports.

A package must also:

(a) Include facilities for saving program files for use in later runs

(b) Allow sensitivity analysis to be carried out.