Mechatronic systems are often comprised of many different components, all operating in different domains of physics. In MCHA3400, a systems approach to engineering is introduced, in the context of safety instrumented systems (SIS). Students are taught to analyse the reliability of interconnected systems and develop safety systems to mitigate unacceptable risk. The designed systems are deployed on embedded hardware (STM32) and validated using processor in the loop (PIL) testing.