Delay problems relating to an invariable number of connections per hour, having invariable holding time and carried by a single outlet

This article follows a previous one published in Volume 41/3 1966 of this magazine. It related to other similar studies, notably those by Fry and Erlang, which assume a constant average number of connections per hour and an invariable holding time. Here it is further assumed that the number of connections is exactly the same for every hour. The mathematical treatment leads to various useful expressions among which are: (a) the delay distribution function, (b) the average total delay per hour, and (c) the average number of delayed calls per hour.