Risk Analysis of Cyber-Physical Systems by GTST-MLD

Cyber-physical systems (CPSs) must consider both components failures and cyber-threats. In this paper, we propose the goal tree success tree master logic diagram (GTST-MLD) to analyze these within the same framework. The benchmark with a conventional attack tree (AT)-bow tie (BT) method of literature shows that GTST-MLD can overcome the limits of conventional AT-BT and requires less information to quantify the risk of a generic CPS, properly managing the scarcity of information on security threats. The method is applied to a CPS comprising of a chemical reactor and its control system that is exposed to cyber-attacks to the SCADA system.