Abstract: A computer-implemented method for making executable specifications in the system development and/or the system validation of a functional system for a target device for a motor vehicle. The method includes: providing a function system including at least one model view of the one or multiple functions for controlling or regulating a target device; providing a selection interface configured for selecting and changing a system part in a provided first model view by a user; transferring and displaying the system part selected and/or changed in the first model view in another model view for the user; providing a specification-and-approval interface designed for selecting and/or checking and/or further adapting the displayed system parts or changes in the other model view and for approving the changes to the system made in the first and/or in the other model view by the user; adopting in an automated manner the approved changes.