Towards Safety Risk Assessment of Socio-technical Systems via Failure Logic Analysis

A thorough understanding of the safety risks of a system requires an understanding of its human and organizational factors, as well as its technical components. Analysis approaches that focus only on the latter without considering, for example, how human decision makers may respond to a technical failure, are not able to adequately capture the wide variety of safety risk scenarios that need to be considered. In this paper, we propose a model-based analysis approach that allows analysts to interpret humans and organizations in terms of components and their behavior in terms of failure logic. Our approach builds on top of CHESS-FLA, which is a tool-supported failure logic analysis technique that supports analysis of component-based system architectures to understand what can go wrong at the system level and to identify the causes (i.e. faulty components). However, CHESS-FLA currently deals only with hardware and software components and thus it is not adequate to reason about socio-technical systems. We therefore provide an extension based on a preexisting classification of socio-failures and combine it with the one used in CHESS-FLA for technical failures, thereby giving birth to a novel approach to analysis of socio-technical systems. We demonstrate our approach on an example from the petroleum domain.