Method for controlling a combustion process in a boiler or furnace or a grinding process in a grinding device, comprising the following steps: - capturing of state variables (st) of the system; - creating multiple, independently from one another, interference models, which describe the effects of interference-based system changes (vt) on the state variables (st) of the system, wherein during the controlling of the process within the system one interference model of the multiple, independently from one another, interference models is considered that momentarily best describes the interference-based system changes (vt); - creating multiple, independently from one another, process models, which describe the effects of setting actions (at) on the state variables (st) of the system, wherein during the controlling of the process within the system one process model of the multiple, independently from one another, process models is considered that momentarily best describes effects of setting actions (at) on the state variables (st) of the system; and - controlling the process within the system by performing setting actions (at) by considering the process model, the interference model and predetermined controlling goals wherein during the creation of the multiple, independently from one another, interference models a distinction is made between effects of short-term interference-based system changes (vt) on the state variables (st) of the system and effects of long-term interference-based system changes (v t) on the state variables (vt) of the system, where the distinction between short-term interference-base changes (vt) and long-term interference-based changes (vt) depends on the process within the system and is done by considering the duration of the controlled process in the system; and wherein the multiple, independently from one another, process models consider multiple assumed future effects of setting actions (at) on the state variables (st) of the system. - capturing of state variables (st) of the system; - creating multiple, independently from one another, interference models, which describe the effects of interference-based system changes (vt) on the state variables (st) of the system, wherein during the controlling of the process within the system one interference model of the multiple, independently from one another, interference models is considered that momentarily best describes the interference-based system changes (vt); - creating multiple, independently from one another, process models, which describe the effects of setting actions (at) on the state variables (st) of the system, wherein during the controlling of the process within the system one process model of the multiple, independently from one another, process models is considered that momentarily best describes effects of setting actions (at) on the state variables (st) of the system; and - controlling the process within the system by performing setting actions (at) by considering the process model, the interference model and predetermined controlling goals wherein during the creation of the multiple, independently from one another, interference models a distinction is made between effects of short-term interference-based system changes (vt) on the state variables (st) of the system and effects of long-term interference-based system changes (v t) on the state variables (vt) of the system, where the distinction between short-term interference-base changes (vt) and long-term interference-based changes (vt) depends on the process within the system and is done by considering the duration of the controlled process in the system; and wherein the multiple, independently from one another, process models consider multiple assumed future effects of setting actions (at) on the state variables (st) of the system.