Functional Block Diagrams (FBDs) are widely used for safety analysis in complex industrial electronic systems, such as smart grids and autonomous platforms. They model stochastic behaviors and cascading dependencies of system components using hierarchical Functional Blocks (FBs). Event Tree (ET) modeling is typically integrated with FBDs to capture complete and partial failure scenarios. This paper introduces \(\mathbb {FETMA}\) (Functional Block Diagram and Event Tree Modeling and Analysis), a software tool for automating FBD construction and safety evaluation. We use \(\mathbb {FETMA}\) to analyze an automated smart grid substation comprising three levels: Station, Bay, and Process. The tool identifies all possible failure and reliability events across these levels. To evaluate \(\mathbb {FETMA}\) ’s scalability, accuracy and execution time, we compare its results with MATLAB-based Monte Carlo simulations, the Isograph software and manual analysis.