A comparison of hazard analysis methods capability for safety requirements generation

Abstract

A safety-critical system comprising several interacting and software-intensive systems must be carefully analyzed to detect whether new functional requirements are needed to ensure safety. This involves an analysis of the systemic properties of the system, which addresses the effect of the interaction between systems and system parts. The paper compares two hazard analysis methods, which are often considered well-suited for such software-intensive systems: the Functional Hazard Analysis (FHA) and Systems-Theoretic Process Analysis (STPA). The focus is on the selection and improvement of the best methods, based on the lesson learned from the comparison of FHA and STPA. The analyses cover the hazard analysis processes, systemic properties, and the criteria of requirements. The paper concludes that STPA is the better choice over FHA. Insights are obtained to align both STPA and FHA methods with the broader topic on risk management, that is, hazard analysis method improvement, cautionary thinking, uncertainty management, and resilience management.

Reliability Modeling and Analysis of a Diesel Engine Design Phase Based on 4F Integration Technology

“…The RSR of each failure mode is calculated using Equation ( 17) and the cumulative frequency probit i of each failure mode can be obtained. Finally, the ranking value WRSR i of the hazard degree of the failure modes is calculated using Equation (18).…”

“…FHA is widely used for the risk assessment of new systems [17]. The authors of [18,19] summarized the advantages and disadvantages of using FHA in the application process. In air transportation, it provides reliable references for civil aviation flight safety to improve the safety and reliability of aircraft resistance runway mechanisms [20] and aviation aircraft systems [21].…”