A method for monitoring and diagnosing components of a rail vehicle, as a singular rail vehicle or as part of a rail vehicle train consisting of a plurality of rail vehicles, with regard to the necessary repair or maintenance, as appropriate, of at least one component, in which at least one measuring device captures at least one measurement variable, which is relevant to an assessment of a necessary repair or maintenance, as appropriate, of the component, is performed in which supplementation, extension, modification or adaptation of evaluation software implemented in an evaluation device is performed based on instructions, data and/or software modules sent from a control center to the evaluation device.