Electronic Reliability in the Field

Over nearly a decade the British Post Office has been operating normal production electronic equipment for the control and routing of calls through the long distance switching network. More recently the first normal production installation of a fully electronically controlled exchange has been cut into service and is the beginning of a regular program for the installation of such exchanges throughout Britain. It is appropriate at this time to review the performance record of the various types of electronic switching equipment, first to confirm that the direction of development is leading toward greater reliability in service, and second to determine whether changes in maintenance organization may be necessary to take advantage of the greater penetration of the more reliable electronic equipment. This paper deals mainly with the lessons to be learned from the performance of the various types of register-transistor equipment used in the long-distance switching network, but also gives some reference to the performance of the TXE 2 electronic exchange.