Method for ensuring or maintaining the function of a complex complete safety-critical system

A method, the use thereof and a computer program product for maintaining the operation of a safety-critical overall vehicle regulatory and/or control system in the event of the occurrence of errors, in which the overall system is divided into system components on the basis of the findings of an error source analysis, in which modes of operation are also defined for the individual system components, and also, in the event of the occurrence of errors in the overall system, the error sources including the signals are analyzed and those methods of operation which are affected by the errors or signals which have occurred are ascertained, wherein on the basis of the error source analysis, those modes of operation of the individual system components which are not affected by the errors are taken and those which ensure an optimum or prescribed response from the overall system are selected.