Considerable fluctuations were observed in the riser temperature of one of the fluid catalytic cracking (FCC) unit of a Southeast Asian refinery. This undesired occurrence has an adverse effect on the performance of the process unit. In the present study, several statistical tools are developed and then used, for the first time, for analyzing routine operating data in order to characterize the dynamics of the riser temperature and other critical variables that may be affecting the riser temperature. Subsequently, a first-principles-based dynamic model of the FCC unit is implemented to closely simulate the FCC unit under investigation. The model is validated by predicting the measured operating data of the FCC unit. This facilitated an in-depth study of the FCC unit, leading to the identification of several strategies for improving the control loop performance of the riser temperature. (c) 2007 Elsevier Ltd. All rights reserved.