Method and apparatus for locating circuit deviations

A system and method for locating circuit deviations or circuit faults in a circuit in respect of a reference circuit. The circuit and the reference circuit are respectively describable by signal-flow graphs, the signal-flow graphs being composed of a multiplicity of interconnected function blocks. The function blocks of the circuit are first assigned to corresponding function blocks of the reference circuit. There are then ascertained those function blocks of the circuit and of the reference circuit for which assignment has not been possible, and which have disposed upstream in the signal flow at least one function block for which assignment has been possible. The result is a boundary between an assigned and a non-assigned region of the circuit and the reference circuit, respectively. A representation of the circuit and reference circuit is preferably produced in which the regions corresponding to the non-assigned function blocks are highlighted.