We present the case study developed in the context of the 4SECURail project and the approach used for its formal modeling and analysis. Starting from a simple SysML/UML behavioral model of the system requirements, three formal models have been developed using three different frameworks, namely UMC, ProB, and CADP/LNT. The paper shows how the different ways to represent and analyze the system from the three different points of view allow us to take advantage of the resulting diversity.