An EWMA model application for quality control analysis in the production of primary aluminium: CVG-Venalum case

In this paper it is used the analysis of series of time in order to study the conduct of the consumption of fluoride of aluminium (AlF3) in four of five lines of production of primary aluminium with competitive quality in the Venezuelan company of Aluminium of the Venezuelan Corporation of Guayana (C.V.G., Venalum). It is performed, in addition, an analysis of the behavior of the consumption of AlF3 under the approach of quality control of temporary information (EWMA) for every line. These analyses will be done in a comparative way, trying to check similarities among four lines of production