Root cause analysis emerges as a discipline that blends logic, evidence, systems thinking, and human insight to help leaders and professionals uncover why problems truly occur—and how to stop them from returning. By combining traditional tools such as 5 Whys, Fishbone diagrams, Pareto analysis, and statistical validation with advanced methods like FMEA, FTA, Bow-Tie, Barrier Analysis, STAMP/STPA, and Causal Loop Modeling, organizations gain a holistic view of failures across technical, human, and systemic layers. The material underscores that modern challenges—AI-enabled systems, healthcare operations, education networks, and industrial automation—demand deeper scrutiny than linear causation can offer. Effective RCA becomes a mindset of curiosity, discipline, and humility, supported by structured workflows, robust CAPA execution, and predictive technologies. The ultimate outcome is operational resilience, reduced waste, safer environments, and healthier teams—an ecosystem where learning replaces blame, and improvement becomes a shared responsibility.