Abstract: A device for the testing of an integrated control system (1) wherein said integrated control system (1) is arranged for controlling a drilling unit (2), said drilling unit (2) arranged for drilling operations, said integrated control system (1) * a drilling control system DCS (3) for controlling a drilling system (7), * said DCS (3) arranged for receiving sensor signals (31) related to said drilling operations and for providing control signals (33) to said drilling system (7) so as for conducting the desired drilling operations, * said DCS (3) arranged for controlling a plurality of drilling operations and comprising a plurality of control subsystems, * said device arranged for the testing for errors in said integrated control system (1) resulting from failures in one or more control subsystems within said integrated control system or from failures in the interactions between control subsystems within said integrated control system (1) or from a combination thereof.