The main contributions (C) claimed in this thesis are improved safety and resilience in complex systems, through: C1. Identified and described new vulnerabilities: Ten general vulnerabilities related to integrated operation, especially related to aspects of remote operations were identified and described. C2. Identified resilient principles: Exploring and making the concept of resilience more operational, through the introduction of seven resilient principles in the oil and gas industry and in railway. C3. Extended accident models, by exploring resilience in successful recoveries. C4. Improved risk assessment by exploring principles from resilience. C5. Documented experiences of the implementation and actual use of methods,rules and approaches to improve safety, security and resilience in complex socio-technical systems in the oil and gas industry, and in the railways.