A method and a device for controlling a process (10), having at least two sub-processes (20, 30), by tracking,
processing and correcting variables for the product, the production means and / or any process media throughout the process line. The process flow for the first sub-process (20) is divided into slices, each slice representing a
specific volume of process flow. At least some of the measured and sampled variable values are related to its specific slice volume. Any variable value obtained is processed using a control and
processing, unit (60) with means for receiving, information on variable values on-line, means for presenting (70) the process flow through the production units, means for dividing the process flow into slices, means for
processing a variable value obtained, including means for relating, the variable value to is specific slice volume, means to develop one or more multivariate models based on variable values for a multiple of slice volumes and means to combine the multivariate model with a processed variable value for a specific slice volume to predict a variable value and / or a quality variable for subsequent second sub-process (30). Corrective actions are executed in the subsequent second sub-process (30) based on a processed variable value from the first sub-process (20) using, actuating, means (80) for execution of corrective action.