An apparatus for monitoring an industrial process comprising a plurality of variables. The apparatus comprises a defining module configured for defining a normal-condition data set may comprise data values of the variables when the industrial process is operating under a normal condition and for defining an abnormal-condition data set may comprise data values of the variables when the industrial process is operating under an abnormal condition; a modelling module configured for modelling a normal-condition model from the normal-condition data set and modelling an abnormal-condition model from the abnormal-condition data set; a plotting module configured for plotting a normal-condition plot from the normal-condition model and plotting an abnormal-condition plot from the abnormal-condition model; and an analysis module configured for analysing live data values of the variables for simultaneous display with the normal-condition plot and the abnormal-condition plot.