The Risk Matrix as an integral part of a SysML-based Security Engineering Approach in the Development of Complex Aircraft Cabin Systems

Security analysis, in parallel with safety analysis, has become an established part of the system development process of modern aircraft cabin systems with an increasing number of hardware and software components and functional complexity. Security analysis is centred on a risk matrix, which in turn defines the risk level in accordance to the preassigned probability of a security event occurrence and the associated effect on the aeroplane with respect to safe flight and landing. Even though a number of different model-based approaches for security analysis exist, a satisfactory solution for integrating the risk matrix into the model remains. Using a model-based security engineering approach this paper describes a solution with a risk matrix being an integral part of a SysML model. For a security assessment the risk matrix is specified within the model and the model supports probability values of the occurrence of a security event and correlates them to the respective effects on the aeroplane.