NISAC has developed N-ABLE™ to assist federal decision makers in improving the security and resilience of the U.S. economy.  N-ABLE™ is a large-scale microeconomic simulation tool that models the complex supply-chain, spatial market dynamics, and critical-infrastructure interdependencies of businesses in the U.S. economy. N-ABLE has been designed in particular to model how U.S. businesses can adapt to and recover from disruptive events; N-ABLE-based insights have been used to evaluate private-industry and if necessary public policies that can mitigate if not prevent significant economic impact.

N-ABLE models the economy at the level of individual firms: each N-ABLE firm has buyers, production supervisors, sellers, and strategic planners who manage their own supply chain through normal conditions, disruption conditions, and recovery. Firms interact with each other in regional markets and in their collective use of the critical infrastructure systems (road, rail, and water transportation; pipelines; electric power; telecommunications).
 

A “Laboratory” for Policy Analysis

N-ABLE has been used to answer economic policy-related questions such as:

  • Which economic sectors and regions of the country are affected most by infrastructure disruptions?
  • How long is it before regional economic impacts affect other regions of the country? Are these cascades caused primarily by regional market effects or critical infrastructure effects?
  • How do the nation’s critical infrastructure systems impact the level of economic impact and time to recovery?
  • Are small firms more vulnerable to disruptive events than large firms? If so, what business continuity and other business strategies can ensure their resilience to these events?
  • What types of firms are most influential toward national economic resilience to these disruptive events?
  • What are the most effective private industry and public policy tactics for economic loss prevention, mitigation, and overall resilience?

Over the past 10 years, N-ABLE has been used in NISAC FAST analyses and in more detailed, longer-term NISAC analyses to analyze the impacts of:

  • electric-power and rail-transportation disruptions on the U.S. chlorine supply chain,
  • hurricanes on large-scale domestic and global chemical supply chains,
  • terrorist acts on commodity futures markets,
  • changes in U.S. border security technologies on U.S. firms that import and export commodities in global supply chains,
  • a pandemic influenza on the U.S. agriculture and food supply chains,
  • pandemic-related household stress on wholesale-to-retail food supply chains, and
  • cost-optimized military-parts global supply chains on war-time equipment uptime.

As one example, NISAC used N-ABLE to estimate the potential impacts to the U.S. chlorine supply of a rail-transport disruption;the N-ABLE supply chain model was composed of 3,000 chlorine producers, packagers, and end users and the supporting rail and road critical infrastructure. Collaborating with chlorine-industry and NISAC subject-matter experts, NISAC conducted hundreds of simulations of disruptions to the transportation infrastructure; results included detailed assessments of which industries and regions of the country would be impacted the most. Furthermore, analytical results indicated that if shippers could optionally expedite their chlorine orders at a cost to themselves, they would create significant benefits to homeland security including:

  • significant reductions in the number chlorine rail cars required for normal operations, thereby significantly reducing the potential of chlorine rail cars being used as a WMD;
  • significant reductions in the time to recovery from a given transport disruption;
  • significant reductions in the “bullwhip” effect created by post-disruption surges in chlorine demand, and
  • lower average on-site inventory levels.

A Flexible, Data-Driven, Collaborative Simulation Architecture

To serve the rapidly changing homeland security scenario arena, N-ABLE uses an extensible data-driven software architecture that allows for rapid development of new models of economic firms, households, critical infrastructure supply chains, and the supporting physical infrastructure systems. And N-ABLE’s client-server architecture allow many subject-matter experts, economic analysts, modelers, and stakeholders to participate in N-ABLE-based scenario analysis.