Assessing dependability and resilience in critical infrastructures: challenges and opportunities

Critical infrastructures (CI) are very complex and highly interdependent systems, networks and assets that provide essential services in our daily life. Most CI are either built upon or monitored and controlled by vulnerable information and communication technology (ICT) systems. Critical infrastructures are highly interconnected systems and often use common ICT components and networks. Therefore, cascading faults and failures are likely events in critical infrastructures. Moreover, such failures can easily spread to other infrastructures and can possibly span to other countries or even continents. Assessing resilience is thus a cornerstone for improving the dependability in critical infrastructures. Due to the complexity and interdependency of such systems many different challenges and opportunities surface when developing methods and tools for resilience assessment. During the last decade both academia and industry developed an increased interest in this research area and a variety of projects with different focus started to emerge. This chapter gives an overview about the main requirements for resilience assessment and discusses the state of the art and emerging research directions. To exemplify the diversity of this research area a special focus is put on different sub-fields with increasing granularity from the fairly general interdependency modeling to the reliability modeling of a Smart-Grid distributed automation network.