System-theoretic approaches view complex systems as integrated wholes rather than isolated parts. Instead of focusing on individual component failures, they analyze dynamic interactions, feedback loops, and control structures to manage safety, risk, and behavior in socio-technical environments. [1, 2, 3, 4, 5]

Core Concepts

Emergent Properties: Traits that belong to the system as a whole and do not exist in any single component.
Control Structures: Hierarchical loops where controllers enforce safety constraints on processes using feedback and actuators.
Safety as Control: Accidents happen due to inadequate control and poor component interactions, not just broken hardware. [1, 2, 3]

Key Methodologies

STAMP: The Systems Theoretic Accident Model & Processes framework redefines accident causality through control and feedback.
STPA: System-Theoretic Process Analysis is a proactive hazard analysis tool used to identify unsafe control actions before failures occur.
CAST: Causal Analysis based on STAMP provides structured accident investigation using system theory principles. [1, 2, 3, 4]