1. A method of determining a relationship between a variable of interest and one or more process variables represented by a corresponding plurality of tags, the method comprising: accessing, by a computer, a data historian comprising historical data from a process, the historical data comprising a variable of interest and a plurality of tags; defining, by the computer, a plurality of bins; retrieving, by the computer, historical data corresponding with the plurality of bins using the data historian; filtering, by the computer, the historical data for each of the plurality of bins using one or more filters to produce filtered historical data; generating, by the computer, an output display using the filtered historical data for the variable of interest and each of the plurality of tags, the output display comprising: an overlay CUSUM chart and; a correlation plot; and determining, by the computer, which of the plurality of tags correlate with the variable of interest using the output display.