A method is provided for the control of valves for flow path control, in particular in a medical treatment machine, having a plurality of processes for the manufacture of flow paths by control of a group of valves, with each process claiming a group of valves suitable for its carrying out for itself so that other processes cannot change the switching state of these valves and with each process itself making a decision on the release of the valves claimed by it. In addition, a method is provided for monitoring the then current and/or scheduled state of a plurality of valves in the flow path control, determining the connections resulting from the switching state of the valves, and comparing the resulting connections with a predetermined number of non-permitted connections.