Systems thinking applied to automation and workplace safety

Abstract

This thesis presents the results of a study to compare Systems-Theoretic Process Analysis (STPA), a hazard analysis methodology based on a new model of accident causation called Systems-Theoretic Accident Model and Processes (STAMP), with the traditional assessments recommended by industry standards for analyzing safety risks in modern manufacturing workplaces that are increasingly incorporating automated systems. These increasingly complex, modern socio-technical systems are introducing new problems in the manufacturing environment that traditional methods of analysis were not designed to analyze. While these traditional methods have previously proven effective at analyzing hazards, the increasing levels of complexity and technological advancement in the factories are surpassing the limits of traditional assessment capabilities. Today's continuous search for opportunities to automate manufacturing process makes this a critical time to ensure that the hazard analysis methodologies in use are capable of providing an effective and efficient analysis. STAMP and STPA were developed specifically to understand and analyze modern, complex socio-technical systems that are introducing new types of accidents with causes beyond traditional component failures. This thesis provides background and discussion of traditional models and methods, of the current industry standard method, and of the proposed method. The current and proposed methods are then used on an actual semi-automated manufacturing process being implemented in an aerospace manufacturing company and analyzed with a set of criteria to determine their effectiveness and efficiency. The results of this analysis determine that STPA is better equipped for the modern manufacturing environment.