Quantitative methods for regulatory control layer selection

► The self-optimizing control ideas are applied to find the optimal controlled variables in the regulatory control layer. ► The regulatory control layer objectives are quantified using the state drift criterion. ► Quantitative method for the regulatory layer selection with fewer closed loops is proposed to minimize the drift in states. ► The proposed method is evaluated on two distillation columns with an objective of minimizing drift in composition states. ► Optimal regulatory layer with one, two or more closed loops is found for two distillation column case studies.