A method for providing output values with associated uncertainties for a flexible modular plant or machine comprising an arrangement of modular entities, wherein uncertainty information associated with an operation of the modular entity is assigned to a plurality of modular entities and input values are provided based on an operation of the modular entities, where a computing unit calculates an output value based on said input values, calculates an input value uncertainty for each input value based on the uncertainty information of the modular entity, and calculates at least one output value uncertainty associated with the output value based on propagation of uncertainty and using the input value uncertainties, and where the output value and the at least one output value uncertainty are output.