Wiley Handbook of Science and Technology for Homeland Security, 4 Volume Set

TIME-DOMAIN PROBABILISTIC RISK ASSESSMENT METHOD FOR INTERDEPENDENT INFRASTRUCTURE FAILURE AND RECOVERY MODELING

GEORGE H. BAKER

James Madison University, Harrisonburg, Virginia

CHARLES T. C. MO

Northrop-Grumman IT, Los Angeles, California

1 INTRODUCTION

The report of the President's Commission on Critical Infrastructures [1, 2] concluded that the nation's physical and economic security depend on critical energy, communications, and computer infrastructures. The Department of Homeland Security has issued national strategy documents for the protection of physical and cyber infrastructures that call for vulnerability assessments of critical infrastructure systems [3, 4]. Even in a world free of malicious activities, such assessments are exceedingly useful to help predict and hopefully prevent outages and costs resulting from natural disasters and normal accidents. Critical infrastructure networks and facilities are subject to many different failure modes. It is important to anticipate these modes, the likelihood of their occurrence, and the relative seriousness of their consequences.

Failures may be due to many causes, intentional and nonintentional, including aging, accidents, and sabotage from insiders or external malefactors. Failures can propagate such that seemingly minor problems may lead to complete functional failure. Of particular concern is the presence of “single-point failure” locations in many known facilities and systems. A question of concern is which failure points ...