A New Functional Systems Theory based Methodology for Process Hazards Analysis

This paper presents a new methodology to cope with complex systems hazards analysis. Process safety is an important problem and has traditionally been tackled as a failure problem. Existing methodologies use a chain of events approach to analyse the system's safety. Today, with more complex and interacting systems, this approach has serious limitations because it does not consider, among others, systemic failures. To overcome these limitations, system based approach called STPA (Systems Theoretic Process Analysis) has been developed at MIT (Massachusetts Institute of Technology). In this work we present this methodology, apply it to a process system and integrate it with the use of functional models, a technique that allows to have a more direct, automatic and comprehensive analysis.