Today, software system development (especially safety critical systems) is a complex task. Any bug in these systems may cause serious and costly problems. In this paper, we propose a formal and automatic approach to refinement platform independent models to more platform specific ones. Using graph transformation systems as background formalism, we can validate the approach to being sure about its correctness. For each level of abstraction, using the designed formal styles, we define proper graph rules to refine the models. In comparison to the existing approaches which only consider the structural parts of the model, our proposal consider the behavioral parts of the models for refinement.