providing a rail vehicle with control software stored in a non-transitory storage medium on the rail vehicle, wherein the control software has basic functions that are needed for a basic operation of any of a multiplicity of rail vehicles, the basic functions being functions relating to a drive of the rail vehicle, to controlling the drive of the rail vehicle, to brakes of the rail vehicle, and to controlling the brakes of the rail vehicle;

wherein the control software has optional functions that are needed to implement a multiplicity of customer-specific requirement profiles, wherein the optional functions are functions other than the basic functions;

wherein embodiments, combinations, and functional sequences of the basic functions and of the optional functions were tested, validated, and approved before implementing the control software in the rail vehicle; and

in a selected one of the rail vehicles, enabling the control software to be modified based on a switching parameter that is individually assigned to one of the optional functions of the control software, wherein the switching parameter determines whether the one of the optional functions of the control software is activated or deactivated and thus whether the one of the optional functions of the control software is included in a range of functions of the control software;

wherein the switching parameter is determined and generated by a manufacturer of the rail vehicles remotely from the selected one of the rail vehicles on a basis of a special customer-specific requirement profile; and

wherein the switching parameter is transmitted via a communication channel

and via an interface to a service engineer who updates the control software in the selected one of the rail vehicles; or

directly to the selected one of the rail vehicles, wherein control devices in the selected one of the rail vehicles automatically implement the switching in the control software.