The development of safety critical systems becomes even harder since the complexity of these systems grows continuously. Moreover, this kind of process involves the use of powerful design methods and precise reliability techniques that utilize dissimilar models and construction policy. In this article we propose a method to unify and enhance this process by linking functional design phase using SysML with commonly used reliability techniques such as FMEA and dysfunctional models construction in AltaRica Data Flow. We present how SysML models can be analyzed automatically in order to produce an FMEA and expose a parallel between SysML models and AltaRica Data Flow ones. The given approach is structured around a database of dysfunctional behaviors that supports the studies and is updated by the obtained results. We exemplify the approach to analyze a system of level controlling of a tank.