Modern methods of technical control based on mathematical statistics methods used at Novokuznetsk Aluminum Plant are considered. The new information-technological system introduced in 2004 allows to evaluate the stability of electrolysis production processes by the following main parameters: cryolite ratio, metal level, electrolyte level and temperature, calcium content, frequency of anodic actions. The application of the new software to control electrolyte composition is shown by means of control charts, Pareto diagrams and histograms. It is revealed that the highest percentage of deviations is observed for the parameters obtained by instrumental measurement (metal level, electrolyte level). Compliance with normative and technical documentation is not a quality criterion. To ensure the stability and maintenance of quality indicators and parameters of the electrolysis process at an acceptable level, a number of measures are proposed.
