Every action plan needs to be based on requirements, that is, what essentially the system must have in order not to suffer from virtual attacks. So, it's time to design what can happen at each end of the project. In this sense, we are talking about identifying, for example, whether an online firewall barrier is needed, or whether everything will be offline, which would not justify the use of a firewall.
Thus, it is what will guide the first ideas for creating the development as a whole, being an extremely important part.