Control apparatus for manufacturing plastics films, in particular for manufacturing plastics flat sheet films, cast films, monoaxially, uniaxially, sequentially biaxially or simultaneously biaxially stretched plastics films, or for manufacturing blown films, including double-bubble films, tri-bubble films or multi-bubble films in general, having the following features: - the control apparatus is designed so as to be at least two-stage, - for this purpose, the control apparatus comprises a) a process model or a process module having an implemented process model on the one hand, and b) a sensor model or a sensor module having an implemented sensor model on the other hand, - the machine-independent process module or process model links or associates process variables and/or product characteristics with production variables with respect to the plastics film to be manufactured, - the machine-dependent sensor module or sensor model links or associates production variables for the plastics film to be manufactured with settable machine variables, - the machine-independent process module or process model and the machine-dependent sensor module or sensor model are or can be mutually associated by production variables, - the process variables and/or product characteristics include one or more values from the group of tensile strength, E-modulus, film thickness, film turbidity and the shrinkage of the film, - the production variables include a plurality of production variables from the group comprising plastics film temperature and film tensile forces acting on the plastics film in the transverse direction and/or longitudinal direction, - the settable machine variables include a plurality of machine variables from the group comprising the cooling water temperature, the heating temperature of heating systems, fan speeds of ventilation means and tensile stresses in the transverse and/or longitudinal direction of the plastics web that is to be drawn off; characterised in that - the process module and/or process model is bidirectional, such that, with respect to specifiable process variables, production variables result that are linked therewith, correlated therewith or abstracted therefrom and, vice versa, for specifiable production variables, process variables for the film treatment result that are linked therewith or abstracted therefrom or correlated therewith, and in that - the sensor model is bidirectional, such that specifiable process variables result in machine variables that are correlated or linked therewith and, vice versa, specifying settable machine variables results in values of production variables that are derived therefrom or linked or associated therewith. - the control apparatus is designed so as to be at least two-stage, - for this purpose, the control apparatus comprises a) a process model or a process module having an implemented process model on the one hand, and b) a sensor model or a sensor module having an implemented sensor model on the other hand, a) a process model or a process module having an implemented process model on the one hand, and b) a sensor model or a sensor module having an implemented sensor model on the other hand, - the machine-independent process module or process model links or associates process variables and/or product characteristics with production variables with respect to the plastics film to be manufactured, - the machine-dependent sensor module or sensor model links or associates production variables for the plastics film to be manufactured with settable machine variables, - the machine-independent process module or process model and the machine-dependent sensor module or sensor model are or can be mutually associated by production variables, - the process variables and/or product characteristics include one or more values from the group of tensile strength, E-modulus, film thickness, film turbidity and the shrinkage of the film, - the production variables include a plurality of production variables from the group comprising plastics film temperature and film tensile forces acting on the plastics film in the transverse direction and/or longitudinal direction, - the settable machine variables include a plurality of machine variables from the group comprising the cooling water temperature, the heating temperature of heating systems, fan speeds of ventilation means and tensile stresses in the transverse and/or longitudinal direction of the plastics web that is to be drawn off; characterised in that - the process module and/or process model is bidirectional, such that, with respect to specifiable process variables, production variables result that are linked therewith, correlated therewith or abstracted therefrom and, vice versa, for specifiable production variables, process variables for the film treatment result that are linked therewith or abstracted therefrom or correlated therewith, and in that - the sensor model is bidirectional, such that specifiable process variables result in machine variables that are correlated or linked therewith and, vice versa, specifying settable machine variables results in values of production variables that are derived therefrom or linked or associated therewith.