There are several types of threats that can affect an industrial system. For a long time, efforts were focused on the functional aspect of the system. However, with the rise of computer technologies and industry 4.0, industrial systems are more prone to software issues and cyber attacks.
This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/securing-your-projects-and-programs-in-siemens-tia-portal