1. A method for modeling behavior in a process plant, comprising: receiving M process variable data sets, wherein M is an integer; calculating statistical data for process variables associated with the M process variable data sets using the M process variable data sets and not using additional process variable data sets; scaling the M process variable data sets using the statistical data; calculating a plurality of intermediate modeling terms using the scaled M process variable data sets; receiving the additional process variable data sets associated with the process variables; scaling the additional process variable data sets using the statistical data; after calculating the plurality of intermediate modeling terms using the scaled M process variable data sets, updating the plurality of intermediate modeling terms using the scaled additional process variable data sets; and calculating a model of the process variable using the plurality of intermediate modeling terms.