This application deals with the automation and computer aided operation including monitoring and control of a pilot plant scale fluid catalytic cracking unit. The operation and monitoring of the pilot plant is carried out through graphical process flowsheets of the actual process which are presented on the screen of a personal computer. All operational results and all manipulating actions are logged and stored in a time sequential indexed file that can be recalled at any time. Through the use of automation and computer software a complex unit such the FCC unit can be operated unattended in long runs giving useful results used for process modeling and model evaluation, catalyst and process condition evaluation. Real experimental results will show the trends and the good comparison of the unit operation to the FCC theoretical estimations.