The twenty-first century is defined by the social and technical hazards we face.A hazardous situation is a condition,or event,that threatens the well-being of people,organizations,societies,environments,and property.The most extreme of the hazards are considered X-Events and are an exogenous source of extreme stress to a system.X-Events can also be the unintended outputs of a system with both positive(serendipitous) and negative(catastrophic) consequences.Systems can vary in their ability to withstand these stress events.This ability exists on a continuum of fragility that ranges from fragile(degrading with stress),to robust(unchanged by stress),to antifragile(improving with stress).The state of the art does not include a method for analyzing or measuring fragility.Given that “what we measure we will improve,” the absence of a measurement approach limits the effectiveness of governance in making our systems less fragile and more robust if not antifragile.The authors present an antifragile system simulation model,and propose a framework for analyzing and measuring antifragility based on system of systems concepts.The framework reduces a multidimensional concept of fragility into a two-dimensional continuous interval scale.