How do you fix a flying computer? Seeking resilience in software-intensive mission systems Report by Trey Herr, Reed Porada, Simon Handler, Orton Huang, Stewart Scott, Robert Lychev, and Jeremy Mineweaser Executive summary Defense organizations, by nature, confront unanticipated and highly impactful disruptions, but must continue to operate using complex mission systems. They must adapt these systems to withstand surprise and accomplish defined objectives despite disruption and the behavior of adversaries. It is crucial to understand a system as more than hardware or software—it is a combination of people, organizational processes, and technologies. Mission resilience is the ability of a mission system to prevent, respond to, and/or adapt to both anticipated and unanticipated disruptions, optimizing efficacy and long-term value. This means overcoming sophisticated cyberattacks and managing the risk of systemic software vulnerabilities, but it also encompasses changing operating environments, adversary innovation, and unexpected failures. Resilient mission systems should have the capacity to continue mission essential operations while contested, gracefully degrading through disruption rather than collapsing all at once.