A system (S) has at least a first and a second self-driving ground working device for combined working of a predetermined operating region (A). An individual ground working device travels autonomously along a random path inside the operating region. The system has at least one base station for communication with the ground working devices. For a method for setting up and operating the system, provision is made that information relating to an operating variable (B) stored in one ground working device is transmitted to further ground working devices, that a ground working device travels autonomously along a random path (W) inside the operating region, independently of another ground working device, by using the operating variable, and that during the operation of the system of ground working devices the behavior of an individual ground working device is adapted as a function of changes in the operating variable.
