Today’s market offers a wide range of available firewalls, there are many manufacturers andeach of them has at least several series of possible solutions. As organisations and companiesseek to protect their assets against current and new hostile threats, the demands for networksecurity increases and drives the development of firewalls forward. With new firewalltechnologies emerging from a wide variety of firewall vendors, choosing the right firewall canbe both costly and time consuming. Requirements for a concrete network are needed to becorrelated with security functionalities, i.e., metrics for firewalls. Incorrect requirementsformulation or their incorrect mapping to metrics can lead to a financial loss or a firewallfailure in providing ...