Abstract: A system and method modifies a dynamic model of a process in a plant for an advanced process control controller wherein the model includes sub models. Performance of the controller is monitored and performance degradation is quantified as the process changes. It is then determined whether a selected number of sub models need updating or the entire model dynamics need updating as a function of the quantified controller performance degradation If a selected number of sub models need updating, an excitation signal is initiated for such sub models to identify new sub models. If the entire model dynamics need updating, a complete perturbation signal is initiated and triggers exhaustive closed-loop identification of entire model. The newly identified model or sub models is incorporated in the controller.