Application of STAMP to Process Industry

Abstract

Hazard identification is one of the most important activities carried out in the Safety Instrumented System (SIS) safety lifecycle [1]. Proper hazard identification and analysis of its risk lays the foundation of the SIS design. The common method for a structured study for the hazard identification is Hazard and Operability Study (HAZOP) study. The concepts of HAZOP are well evolved and applied for over five decades. The basic premise for HAZOP considers plant design is mature enough and sufficient design information on the plant operation is available. HAZOP process involves breaking down of complex process into simpler sections which are termed as nodes. These individual nodes are then studied for identifying the potential hazards and operability problems. STAMP (System-Theoretic Accident Model and Processing) [2] is accident causality model based on systems theory. STPA (System Theoretic Process Analysis) is one of the STAMP based tool which is a relatively new hazard analysis technique based on an extended model of accident causation. STPA is a proactive analysis method that analyzes the potential cause of accidents during design development so that hazards can be eliminated or controlled. Conventional studies like HAZOP considers deviations or component failures as cause for what may go wrong and cause accident. STPA assumes that accident may also be caused due to unsafe interactions of the system components, none of which have failed.