In contemporary society, risk is omnipresent and closely linked to our safety, now a major priority. Individuals evaluate and accept risks based on personal criteria. This thesis explores risk assessment in complex environments and the impact of third-party actions and events. The holistic risk assessment concept (HoloRisk) aims to develop a methodology and model considering elements beyond the individual's direct influence for personalized risk assessment. HoloRisk envisions future capabilities to collect and process vast amounts of real-time data about individuals and their environments. This assessment hinges on the interaction and correlation of these data. The thesis proposes integrating various data sources to identify complex relationships between different risk factors, surpassing traditional methods that fail to capture the dynamic nature of modern risks. Practical applications, such as traffic management, demonstrate HoloRisk's real-world benefits. In conclusion, the thesis significantly advances our understanding of risks in an interconnected world, anticipating challenges and opportunities in an era of rapid technological change and providing a solid framework for addressing these issues.