This paper describes an integral automation structure for a steam generation plant, based on hybrid systems. We will describe the principal elements to achieve the automation: the image of the system under control (set of operation conditions and its behavior), and the supervisor with its decision system implemented as a hierarchical structure. This development permits the implementation of the complete control strategy for the whole plant using the technology in place. The results shown were obtained from the simulation of a real process, and it is considered as a validation in order to implement the proposed scheme.