Modeling Resiliency and Its Essential Components for Cyberphysical Systems
Janusz Zalewski, Steven Drager, William McKeever, Andrew J. Kornecki, Bogdan Czejdo
DOI: http://dx.doi.org/10.154392015414
Citation: Position Papers of the 2015 Federated Conference on Computer Science and Information Systems, M. Ganzha, L. Maciaszek, M. Paprzycki (eds). ACSIS, Vol. 6, pages 107–114 (2015)
Abstract. This position paper presents an initial approach related to modeling resiliency for cyberphysical systems. It discusses the concept and the definitions of resiliency and outlines the process of building a model of resiliency. Through analogies with feedback control and fault tolerance, the Design for Resilience is addressed, where the design of the controller part of a cyberphysical system needs to account for potential safety hazards and security threats, with awareness of its internal faults and vulnerabilities. This model is validated against other known approaches to modeling resilience described in the literature, and then a discussion of the resilience metrics is presented. The paper concludes with presenting the strategy of modeling resiliency, based on the assumption that one cannot guarantee absolute protection against attacks, breaches, or failures, but can aim at providing successful recovery after disruptions. Involving safety and security as essential resiliency components, an extended model is proposed involving an attacker, suggesting appropriate performance metric reflecting the distance between the normal state and the degraded state. A simulation tool M\"obius, a model-based environment developed at the University of Illinois, is considered in helping to evaluate resiliency under various operational scenarios.