Download This PaperAugmenting a Hazard Analysis Method with Error Propagation Information for Safety-Critical Systems
35th International System Safety Conference, August 21-25, Albuquerque, New Mexico, USA
10 Pages Posted: 1 May 2020
Date Written: 2017
Abstract
Context: Safety-critical systems need specific development activities in the software development life cycle to ensure that the system will operate safely. Objective: The overall objective of this research is to develop a safety analysis method that provides a deeper analysis of the system under review. Problem: Current safety analysis methods do not use error information to identify faults. Method: We augmented the STPA with error propagation information derived from the architecture description of a system represented in the Architecture Analysis and Design Language. In this study, we investigated how an error ontology can be used to assist in identifying errors and how those errors propagate among components. The error may or may not lead to a hazard in the system. It depends on its context. The key principle of our method is that an error analysis of a domain represents the root causes of hazards in the domain. Using that analysis hazards may be identified. Results: The results of our studies have shown that tracing errors leads to finding hazards and additional information in the system that other methods miss. Conclusions: By augmenting existing hazard analysis methods with early design information, we are able to find more hazards, unsafe control actions, safety constraints and specific causes.
Keywords: STPA, Error Ontology
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