This paper presents the configurations and architecture of ABB’s state-of-the-art Integrated Blend control, optimization and planning system implemented at two PEMEX refineries in Cadereyta and Tula in Mexico. The blending control system implemented at PEMEX refineries is very sophisticated both in field equipment and control software system. The blending system involves on-line analyzers (NIR) for both stocks and product and the control software system is a full integration of all three levels of control, namely, regulatory blend control, advanced on-line control and optimization and off-line optimization and planning systems. The regulatory blend control (RBC) is implemented in Fisher DCS ProVox and other blend control higher levels, advanced on-line control, optimization and planning, on HP 9000/715 work-stations.