A proposed validation framework for the system theoretic process analysis (STPA) technique

Abstract

Validation is a prominent challenge in the domain of risk management in general, and hazard analysis in particular. Practitioners have highlighted a lack of clear guidance on how to perform validation of hazard analyses, who should be involved, and when to stop the validation process. Aiming to contribute to addressing this issue, this study proposes a validation framework for the System Theoretic Process Analysis (STPA) technique, based on foundational concepts in risk analysis and prior theoretical work on validation in related disciplines. STPA, which is a hazard analysis technique based on System-Theoretic Accident Model and Processes (STAMP) accident causality model, is selected due to its increasing popularity in different industries, and because no validation frameworks have yet been proposed for this technique. The proposed STPA validation framework aims to support a systematic assessment of the analysis's comprehensiveness, accuracy, and credibility. It consists of a set of theory-based concepts that are elaborated as guide questions, each focusing on different aspects of STPA. The framework employs a formative approach, i.e., it aims to help stakeholders systematically reason about the analysis and advise on improvements or further elaboration. To develop this framework, theoretical validation concepts in the pertinent literature in risk science, social science, and operations research, system dynamics, and simulation modeling disciplines have been used. It is recognized that the proposed framework should be further tested to confirm its practical usefulness, and it should be investigated whether it indeed improves the hazard analysis in terms of the envisioned functions.