Abstract
One important problem in the evaluation of the busy-hour service of telephone exchanges is the investigation of telephone traffic on both direct final and alternative final routes. Erlang and Wilkinson have produced complicated mathematical formulas that can be used for such an investigation. This paper describes an interactive menu-driven computer program that implements the theory and acts as an easy-to-use investigative tool for students and engineers in the field. The program is developed in a modular construction on an IBM-PC microcomputer, using TURBO Pascal. To illustrate the use of the program, the paper describes its application to the final routes of some telephone exchanges in Saudi Arabia.