A self-tuning hierarchical controller in which a Fuzzy logic controller supervises the control actions of a conventional PID has been proposed. implemented and presented in this paper. The controller has been applied to a control study of Fluid Catalytic Cracking unit (FCCU) riser temperature. and regenerator temperature respectively. https://www.roneverhart.com/4628-P1028-5-Hole-Flat-Cross-Splice-Plate-FittIng-for-Unistrut-Channel/