Choose your disaster: Hurricane Katrina, the World Trade Center attacks, the SARS outbreak. In recent years, thousands of companies have unexpectedly found their properties damaged, operations interrupted, workers displaced, and critical records lost due to disasters natural or otherwise.

Even as many companies now try to assess a wide variety of risks, calculating the likelihood and consequences of a disruption to business continuity has proven to be a fiercely difficult challenge. Indeed, the Gartner Group research firm has found that 40 percent of organizations that experience a disaster go out of business within two years.