Abstract: A computer system for dynamic service processor exchange comprising a first, active service processor connected by a network and a maintenance unit (CMU) to a central system (4) and to a second, backup service processor (2). Each service processor has, in addition to an operating system, a supervisor processor and at least one service broken down into two portions, namely a "body" portion comprising a service processor and a "presentation" portion comprising an interface with the operator allowing a display of the window type with a menu bar. Each service processor further has a maintenance station handler interface (10,20) for processing communications with other service processors by means of the maintenance unit (CMU). The supervisor processor manages the numbers in question and the services, starts the services, and has access to a system configuration table.