Abstract: For administering and maintaining a greatest variety of communication systems having a greatest variety of configuration levels and function versions, a modularly structured personal service computer can be connected thereto locally or via communication networks. The adaptability to the greatest variety of communication systems is achieved with the assistance of a software concept wherein administration and maintenance instructions that administer and maintain communication systems are generated individually associated to a communication system and under the control of the user surface and are communicated to the respective communication system. The software concept is based on a software structure comprising four program structures that can be modified by removing or adding program modules given the least influencing of the implemented program modules and that substantially enhances the modularity and adaptability of the personal service computer.