Since the eco-efficiencies of all industrial processes/plants have become more and more important, engineers need to find a way to integrate process design, process control and measurements of eco-efficiency. The thermodynamic concept of Exergy can be used to analyze a process in terms of its efficiency. The Relative Exergy Array (REA) that measures both the relative exergetic efficiency and the controllability of a process has been proposed by Montelongo-Luna et al. (2011). The REA can be used for quick comparison between several process/control structure candidates. It is very common that the industrial unit/process includes some recycle loops. The recycle effect on REA is investigated in this paper through two process case studies. Simulation results show that the REA without consideration of the recycle loop may mislead the selection of control configuration. Recycle loop should be considered for selection of control configuration. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.