Abstract: Computer-controlled switching systems, such as telephone switching systems, like the No. 4ESS™, are extremely complex. Such systems routinely require millions of bytes of program instruction and millions of bytes of data to function. When a system is lost, or is rendered inoperative, reassigning the tasks of the system to a backup or replacing the system can be simplified if a backup copy of the program and data is available. Automatically performing the tasks under program control greatly reduces the complexity of the tasks and improves system reliability. Automatic backup of complex system software and data files is accomplished under program control which periodically directs a switching system to copy its files onto a remotely located administration computer from which the backed up information can be retrieved in the event of a system failure.