Engineered Resilient Systems Model Applied to Network Design

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of resilient complex engineered systems throughout their lifecycle. There is growing literature with qualitative definitions of resilience and quantitative models for systems, but these focus typically on systems with one performance measure. In application, many systems have multiple functions and multiple performance measures. This research uses a quantitative resilience framework for ERS that includes system design options, reliability, external threats, vulnerabilities, responses, and consequences assessed on multiple system performance measures. This paper applies the ERS framework to designing resilient networks

Modeling Supply Chain Resiliency

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of complex engineered systems throughout their life cycle. There is a growing literature with qualitative definitions of resilience and quantitative models for systems with one performance measure. This paper uses a quantitative resilience framework (the Framework for ERS) that includes system design options, reliability, threats, vulnerabilities, responses, and consequences assessed in multiple system performance measures. The framework assists in establishing a model for any system to evaluate resiliency. This paper applies this framework using Multiple Objective Decision Analysis (MODA) to evaluate resiliency tradeoffs in designing supply chain and logistics networks to help decision makers increase the resilience of their supply chain networks. By using the MODA framework, decision makers can identify and evaluate multiple design options for a supply chain network

General Design Principles for Resilience and Adaptive Capacity in Legal Systems--With Applications to Climate Change Adaptation

No force has put more pressure on the legal system than is likely to be exerted as climate change begins to disrupt the settled expectations of humans. Demands on the legal system will be intense and long-term, but is the law up to the task? If it is, it will at least in part be because the legal system proves to be resilient and adaptive. The question this Article explores, therefore, is how to think about designing legal instruments and institutions now with confidence they will be resilient and adaptive to looming problems as massive, variable, and long-term in scale as climate change. Drawing from the body of resilience theory forged in natural and social sciences, this Article is the first to synthesize resilience theory in a framework relevant to lawyers and explore the general design principles it suggests for legal systems. Part I examines resilience - what it is and how to design for it in legal systems. It examines the normative dimensions of resilience and makes important distinctions between resilience of legal systems, resilience of laws they produce, and resilience of the other social and natural systems law addresses. Part II provides the theoretical context and design principles for adaptive capacity, focusing on adaptive management theory as an example for legal design. Part III suggests applications of these general principles to the challenge of designing law for responding to climate change, arguing that climate change adaptation law should draw from theories of adaptive management, dynamic federalism, new governance, and trans-governmental networks

Multi-Layer Cyber-Physical Security and Resilience for Smart Grid

The smart grid is a large-scale complex system that integrates communication technologies with the physical layer operation of the energy systems. Security and resilience mechanisms by design are important to provide guarantee operations for the system. This chapter provides a layered perspective of the smart grid security and discusses game and decision theory as a tool to model the interactions among system components and the interaction between attackers and the system. We discuss game-theoretic applications and challenges in the design of cross-layer robust and resilient controller, secure network routing protocol at the data communication and networking layers, and the challenges of the information security at the management layer of the grid. The chapter will discuss the future directions of using game-theoretic tools in addressing multi-layer security issues in the smart grid.Comment: 16 page

Weak Resilience of Networked Control Systems

In this paper, we propose a method to establish a networked control system that maintains its stability in the presence of certain undesirable incidents on local controllers. We call such networked control systems weakly resilient. We first derive a necessary and sufficient condition for the weak resilience of networked systems. Networked systems do not generally satisfy this condition. Therefore, we provide a method for designing a compensator which ensures the weak resilience of the compensated system. Finally, we illustrate the efficiency of the proposed method by a power system example based on the IEEE 14-bus test system

Resilient Autonomous Control of Distributed Multi-agent Systems in Contested Environments

An autonomous and resilient controller is proposed for leader-follower multi-agent systems under uncertainties and cyber-physical attacks. The leader is assumed non-autonomous with a nonzero control input, which allows changing the team behavior or mission in response to environmental changes. A resilient learning-based control protocol is presented to find optimal solutions to the synchronization problem in the presence of attacks and system dynamic uncertainties. An observer-based distributed H_infinity controller is first designed to prevent propagating the effects of attacks on sensors and actuators throughout the network, as well as to attenuate the effect of these attacks on the compromised agent itself. Non-homogeneous game algebraic Riccati equations are derived to solve the H_infinity optimal synchronization problem and off-policy reinforcement learning is utilized to learn their solution without requiring any knowledge of the agent's dynamics. A trust-confidence based distributed control protocol is then proposed to mitigate attacks that hijack the entire node and attacks on communication links. A confidence value is defined for each agent based solely on its local evidence. The proposed resilient reinforcement learning algorithm employs the confidence value of each agent to indicate the trustworthiness of its own information and broadcast it to its neighbors to put weights on the data they receive from it during and after learning. If the confidence value of an agent is low, it employs a trust mechanism to identify compromised agents and remove the data it receives from them from the learning process. Simulation results are provided to show the effectiveness of the proposed approach

A novel "resilience viewpoint" to aid in engineering resilience in systems of systems (SoS)

Designing evolutionary systems to meet stakeholder expectations on safety, reliability and overall resilience is of great importance in an age of interconnectivity and high dependency systems. With incidents and disruptions becoming more frequent in recent years, the requirement for systems to demonstrate high levels of resilience given the economic, political and temporal dimensions of complexity, resilience is of great significance today. Systemic resilience is of high importance at the global level. Therefore, the role of the system engineer and architect is becoming more demanding due to the need to consider requirements from a broader range of stakeholders and to implement them into early conceptual designs. The early modeling process of all systems is common ground for most engineering projects, creating an architecture to both understand a system and to design future iterations by applying model-based processes has become the norm. With the concept of systems-ofsystems (SoS) becoming common language across multiple engineering domains, model-based systems engineering techniques are evolving hand-in-hand to provide a paradigm to better analyse current and future SoS. The intrinsic characteristics of the constituent systems that make up the SoS make the challenge of designing and maintaining the reliability and resilience of a systems extremely difficult. This paper proposes a novel viewpoint, within an architecture framework (based around DoDAF, MoDAF and UPDM) to aid systems architects explore and design resilient SoS. This is known as the Resilience Viewpoint. Much of the research in the area is focussed on critical infrastructure (CI), looking at telecommunication networks, electric grid, supply networks etc, and little has been done on a generalizable tool for SoS architecture analysis, especially using existing modeling languages. Here, the application of the ‘Resilience Viewpoint’ is demonstrated using a case study from an integrated water supply system of systems, to portray its potential analytical capabilities