This paper introduces an idea of a validatable architecture for software intensive industrial automation systems. The validation means will be provided through the formal modeling of automation systems, including both modeling of uncontrolled behavior of the equipment and modeling of the control system. This will be achieved through the facilitated reuse and integration of basic models to the models of complex systems. The validation will be empowered by advanced formal verification techniques combined with more usual testing by simulation. The discussed architecture bases on the latest developments in automation such as IEC61499 standard, on the latest trends in model-based software engineering, e.g. UML, and on modular modeling concepts of Condition/Event Systems