This chapter describes a virtual supervisory control and data acquisition (SCADA) security laboratory and the improvements made using Simulink. The laboratory was initially constructed using virtual devices written in Python that simulate industrial processes, emulate control system ladder logic functionality and utilize control system communications protocols. However, given the limitations of Python programs with regard to modeling industrial processes, an improved model was constructed using the Simulink modeling environment. Custom and commercially-available human-machine interfaces used in real-world SCADA environments were deployed in the new laboratory. In addition, various attacks were developed and implemented against the virtual SCADA system. The behavior of the improved laboratory and its earlier version are compared against the physical system after which both were modeled.