Human error remains a dominant contributor to accidents and near-miss events in high-risk construction and industrial activities, where complex socio-technical systems, hazardous environments, and time-sensitive operations intersect. This presents a conceptual framework for human error causation that integrates individual, organizational, and system-level determinants to explain how errors emerge, propagate, and result in adverse safety outcomes. Drawing on established theories such as Reason’s Swiss Cheese Model, Human Factors Analysis and Classification System (HFACS), and systems engineering perspectives, the framework conceptualizes human error not as isolated unsafe acts, but as the outcome of interacting latent conditions and active failures embedded within project delivery systems. At the individual level, the framework accounts for cognitive limitations, skill-based errors, rule-based mistakes, violations, fatigue, and risk perception, recognizing how stress, workload, and competence shape frontline behavior. At the organizational level, factors such as safety leadership, contractor governance, training adequacy, communication quality, and production pressure are positioned as critical enablers or inhibitors of safe performance. At the system and environmental level, the framework incorporates design complexity, task variability, technological interfaces, regulatory context, and dynamic site conditions that influence human reliability. A key contribution of the framework is its emphasis on feedback loops and coupling effects, illustrating how weak governance, fragmented contractor management, and inadequate learning mechanisms can amplify minor errors into major incidents. The framework also accommodates modern industrial realities, including subcontracting chains, digital safety systems, and automation-assisted work processes, thereby extending traditional human error models to contemporary high-risk project environments. By providing a structured lens for analyzing accident causation, the framework supports proactive hazard identification, targeted safety interventions, and evidence-based policy development. Ultimately, this conceptualization advances safety science by shifting focus from individual blame toward systemic resilience, enabling organizations to design safer work systems and sustainably reduce human error in construction and industrial operations.