Zachary A. Collier

Risk-based standards: integrating top-down and bottom-up approaches

In response to rapidly changing threats posed to increasingly complex socio-technical systems, many in the government and private sector have called for protection through risk-based standards. However, given the nature of these dynamic and uncertain threats, traditional risk assessment techniques may not be sufficient. Instead, there is a critical need for an integrated approach in which decision analytic techniques are used to assess evidence-based data with the values and preferences of decision makers. We point to three examples in the fields of nuclear power regulation, nanotechnology, and cybersecurity, where risk-based approaches (bottom–up) have been combined with decision analysis (top–down) to guide decision makers toward risk management policies that manifest both the best available evidence and the plurality of values within a society.

Systems engineering framework for cyber physical security and resilience

AbstractAs our infrastructure, economy, and national defense increasingly rely upon cyberspace and information technology, the security of the systems that support these functions becomes more critical. Recent proclamations from the White House, Department of Defense, and elsewhere have called for increased resilience in our cyber capabilities. The growth of cyber threats extends well beyond the traditional areas of security managed by Information Technology software. The new cyber threats are introduced through vulnerabilities in infrastructures and industries supporting IT capital and operations. These vulnerabilities drive establishment of the area of cyber physical systems security. Cyber physical systems security integrates security into a wide range of interdependent computing systems and adjacent systems architectures. However, the concept of cyber physical system security is poorly understood, and the approach to manage vulnerabilities is fragmented. As cyber physical systems security is better understood, it will require a risk management framework that includes an integrated approach across physical, information, cognitive, and social domains to ensure resilience. The expanse of the threat environment will require a systems engineering approach to ensure wider, collaborative resiliency. Approaching cyber physical system security through the lens of resilience will enable the application of both integrated and targeted security measures and policies that ensure the continued functionality of critical services provided by our cyber infrastructure.

A Decision Analytic Approach to Exposure-Based Chemical Prioritization

The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical’s life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies.

Tiered guidance for risk-informed environmental health and safety testing of nanotechnologies

Provided the rapid emergence of novel technologies containing engineered nanomaterials, there is a need to better understand the potential environmental, health, and safety effects of nanotechnologies before wide-scale deployment. However, the unique properties of nanomaterials and uncertainty regarding applicable test methods have led to a lack of consensus regarding the collection and evaluation of data related to hazard and exposure potentials. Often, overly conservative approaches to characterization and data collection result in prolonged, unfocused, or irrelevant testing, which increases costs and delays deployment. In this paper, we provide a novel testing guidance framework for determining whether a nanotechnology has the potential to release material with nano-specific parameters that pose a risk to humans or the environment. The framework considers methods to categorize nanotechnologies by their structure and within their relevant-use scenarios to inform testing in a time- and resource-limited reality. Based on the precedent of dredged sediment testing, a five-tiered approach is proposed in which opportunities are presented to conclude testing once sufficient risk-related information has been collected, or that the technology in question does not require nano-specific scrutiny. A series of screening stages are suggested, covering relevant aspects including size, surface area, distribution, unique behaviors, and release potential. The tiered, adaptive guidance approach allows users to concentrate on collecting the most relevant data, thus accelerating technology deployment while minimizing risk.

Cybersecurity Standards: Managing Risk and Creating Resilience

A risk-based cybersecurity framework must continuously assimilate new information and track changing stakeholder priorities and adversarial capabilities, using decision-analysis tools to link technical data with expert judgment.

Stakeholder engagement in dredged material management decisions

Dredging and disposal issues often become controversial with local stakeholders because of their competing interests. These interests tend to manifest themselves in stakeholders holding onto entrenched positions, and deadlock can result without a methodology to move the stakeholder group past the status quo. However, these situations can be represented as multi-stakeholder, multi-criteria decision problems. In this paper, we describe a case study in which multi-criteria decision analysis was implemented in a multi-stakeholder setting in order to generate recommendations on dredged material placement for Long Island Sounds Dredged Material Management Plan. A working-group of representatives from various stakeholder organizations was formed and consulted to help prioritize sediment placement sites for each dredging center in the region by collaboratively building a multi-criteria decision model. The resulting model framed the problem as several alternatives, criteria, sub-criteria, and metrics relevant to stakeholder interests in the Long Island Sound region. An elicitation of values, represented as criteria weights, was then conducted. Results show that in general, stakeholders tended to agree that all criteria were at least somewhat important, and on average there was strong agreement on the order of preferences among the diverse groups of stakeholders. By developing the decision model iteratively with stakeholders as a group and soliciting their preferences, the process sought to increase stakeholder involvement at the front-end of the prioritization process and lead to increased knowledge and consensus regarding the importance of site-specific criteria.

Sustainable roofing technology under multiple constraints: a decision-analytical approach

Recent efforts in the private and public sectors to move toward enhanced sustainability in the built environment have prompted the need to quantify and assess trade-offs among relevant sustainability metrics. Within the US military, for instance, many technological improvements are available to facilitate the achievement of net-zero goals for installations. These technologies must be assessed based on numerous performance criteria, and these technology selection decisions are difficult to make unaided. This paper seeks to demonstrate the use of decision-analytical techniques in which sustainable roofing technology alternatives (reflective, vegetated, or solar roofs) can be properly framed and assessed while evaluating the trade-offs between multiple performance criteria. Multi-criteria decision analysis methods are used to assess the impact of technology alternatives on sustainability framed within the popular concept of the triple bottom line (economic, societal, and environmental concerns). The framework developed in this paper can be applied to other sustainability technologies (energy, water, waste) or portfolios of numerous technologies.

A weight of evidence assessment approach for adverse outcome pathways.

The adverse outcome pathway (AOP) is a framework to mechanistically link molecular initiating events to adverse biological outcomes. From a regulatory perspective, it is of crucial importance to determine the confidence for the AOP in question as well as the quality of data available in supporting this evaluation. A weight of evidence approach has been proposed for this task, but many of the existing frameworks for weight of evidence evaluation are qualitative and there is not clear guidance regarding how weight of evidence should be calculated for an AOP. In this paper we advocate the use of a subject matter expertise driven approach for weight of evidence evaluation based on criteria and metrics related to data quality and the strength of causal linkages between key events. As a demonstration, we notionally determine weight of evidence scores for two AOPs: Non-competitive ionotropic GABA receptor antagonism leading to epileptic seizures, and Antagonist-binding and stabilization of a co-repressor to the peroxisome proliferator-activated receptor α (PPARα) signaling complex ultimately causing starvation-like weight loss.

Decision framework for evaluating the macroeconomic risks and policy impacts of cyber attacks

Abstract Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape.

Guidance for Developing Coastal Vulnerability Metrics

ABSTRACT Wamsley, T.V.; Collier, Z.A.; Brodie, K.; Dunkin, L.M.; Raff, D., and Rosati, J.D., 2015. Guidance for developing coastal vulnerability metrics. Appropriate coastal zone management and storm-damage risk reduction requires the assessment of vulnerability in natural and human environments. Confusion arises, however, as vulnerability is conceptualized in many different ways and is closely related to other concepts such as risk and resilience. This paper defines nomenclature, presents a conceptual definition of vulnerability, and lays out a proposed conceptual approach for identifying and defining meaningful metrics to ensure a complete assessment of coastal vulnerability. While the focus of this paper is developing metrics for assessing vulnerability to coastal storms, the approach is valid for a wide range of systems and hazards at multiple scales and can explicitly consider the impacts of climate change. The approach is demonstrated through application to a simply coupled human-environment system on the coast and explicitly considers natural and nature-based features.