Some systems are resilient - they recover from unanticipated large scale perturbations and continue to exist - while others are not. We started a new project called 'Systems Resilience' that aims to study underlying principles of resilience. We study a wide variety of domains, such as biology, ecology, economics, engineering, sociology, and business management, and extract common characteristics that differentiate resilient systems from non-resilient ones. We are building a mathematical model to represent these characteristics and to quantify resilience. © 2013 IEEE.