Prioritizing assets in critical infrastructure systems

Abstract

Prioritizing is a fundamental task in capital facilities planning and finance. The protection of critical infrastructure systems, essential systems that underpin our society’s “national defense, economic prosperity and quality of life” (President’s Commission 1997), challenges the traditional methods used for prioritizing capital projects. The critical infrastructure systems identified in the various homeland security official documents are vast and complex systems which include among others, transportation, water supply, telecommunications1. The national interest in these systems is clear, protecting these systems from “incapacity or destruction”. In effect, the national interest in these systems is to ensure that these systems are resilient and less vulnerable to potential threats, disasters, or accidents. The National Strategy for the Physical Protection of Critical Infrastructures and Key Assets (Office of the President 2003) requires government agencies as well as the private sector to identify and prioritize assets most essential to the nation’s economic and social well-being. Traditional methods for prioritizing or selecting capital projects for investment fall into two categories, economic evaluation methods and more multicriteria approaches based on expert or departmental judgments, broad categories of need, urgency of need criteria, or program priorities, or goals. (Vogt 2004) Although the multicriteria methods could be applied to prioritize investments in critical infrastructures, such methods are difficult to apply to vast and complex systems often national in scale, and do not necessarily capture the systems or network aspects of the projects. In this paper, I first review and discuss major approaches to prioritization. I then focus on prioritizing system components and networks of critical infrastructures, focusing on Lewis’s network theory (2006) approach to prioritize and invest for protection of nodes in critical infrastructure networks, and also review network interdiction approaches. Based on the limitations of the approaches reviewed, the final part argues that an enhanced systems analysis approach based on stock and flow diagrams would retain more information of the systems as systems and as networks than the more abstract network modeling.