Challenges in Formal Analysis of Resilience: Capturing the Tradeoff Between the Chance of Failure and the Cost of Success

Abstract There is growing interest in the concept of Resilience and balancing resources spent on increasing resilience at the expense of efficiency. From a logical perspective we are interested in formally representing key features of resilience, design principles supporting resilience, and methods to verify system resilience given a formal (in some logic) representation. As background and motivation we review notions of resilience in the context of a variety of systems–digital, natural, societal–along with some examples. We identify some key features of resilience and discuss challenges in developing formal models. After a review of commonly used modeling formalisms and verification problems, we propose an extension that allows modeling resilience features and expressing associated verification problems. We further connect resilience with chance and money by comparing resilience features to principles expressed by the Zurich axioms.