An entity to be validated for consistency is loaded into the buffer of the consistency service, a signal to verify the existence of a specific data set of an IT system is then sent by the consistency service to the IT system holding the entity to be validated for consistency, and the consistency validating information is stored in the output means, said consistency validating information depending on the signal being sent back to the consistency service.The consistency of data stored in various IT systems is checked prior to attempting to access it. Errors by calling a service or functionality that would require access to data that is not available or that is inconsistent can therefore be avoided.