Human and Organizational Performance (HOP) is a safety philosophy that emerged from the Nuclear Energy Sector in North America in the recognition that human error is normal and will happen and that systems should be designed to be more resilient to these errors. The principles of HOP were developed over time by industry professionals with various science academics who observed the need for a shift in traditional thinking about safety and reliability in organizations. The principles of HOP have been influenced by various sources, including the INPO/DOE (Institute of Nuclear Power Operations/Department Of Energy) handbook, and continue to evolve over time. These principles have been used to create a philosophical shift in thinking about how people behave in organizations and how organizations function best with the workers in the organization. HOP encourages operational and organizational learning and emphasizes the importance of learning from past experiences and mistakes, learning from normal everyday work, and the role of leadership in creating a safe and open environment for this learning to happen.