Maintenance of system software on a wide area network of mainframes

A method is suggested for managing and maintaining the basic software in a network from a central installation, thus offering great saving of effort, with nearly no degradation in the service level. The method is based on a small number of model systems (software), which are installed at the central installation. Each remote installation is associated with a specific model system and is called a target system. Any maintenance operation which is required by one of the target systems is applied in the model system, tested there, and eventually exported to all target systems, rather than reinstalled in each installation. Adding a junction to the network requires almost no additional work