This work presents a model for UOP Coker Complex Hydrotreating Process using Aspen HYSYS Petroleum Refining module. The model depends on routinely taken industrial data of process streams during normal operating conditions. Acquired data sets have been tested and screened in order to ensure data validity for building the model and avoiding erroneous results. A detailed kinetic model of hydrotreating reactions in the reactor has been applied. The trickle bed reactor (TBR) model has been validated using 3 months of industrial plant data. In addition, rigorous tray-by-tray simulations for hydrogen sulfide absorption tower and TBR effluent fractionation tower have been utilized to match the performance of the plant's towers. The model has been used then for studying the effects of different process variables on the plant performance. In addition, the model has been used in optimizing the operating conditions of the process. This optimization showed a potential for notable savings of fuel and energy consumption in the process, while increasing the process productivity.