Automation engineering is an important component of modern industrial systems that focuses on the development, analysis, optimisation, and implementation of complex systems to provide safe, economically viable, and efficient processes. Automation engineering seeks to eliminate as much as possible human intervention into the process. However, it should be noted that this does not mean that humans are not required to monitor and assist with the running of the process; it simply implies that the mundane, often repetitive, tasks are delegated to computer systems that are better suited for performing such work. In order to understand automation engineering, it is important to briefly review its long history, its main principles, and its foundations.