Research On STPA-Based Hazard Analysis Method Of IMA Platform Application System

Integrated Modular Avionics(IMA) architecture is a new phase in the development of avionics system. The extensive application of IMA benefits the aircraft developer in terms of flexibility and efficiency. Applications and platforms can be produced by different provider and then integrated into the whole system, which is one of important benefit of the IMA architecture. The development and safety assessment process are separated from system development as well as providers, which might hold a different view about the safety requirement of system, and make safety analysis of IMA becomes very complicated. Traditional chain-of-failure events causality model hazard analysis techniques treat software application and the hardware platform as a whole, and mainly consider about component failures. This works well with federated Avionics. But, when it comes to software-intensive systems like IMA, it could risk the potential of underestimating the effect of dysfunctional component interactions, which has been playing a critical role in system accidents. Although the safety of IMA is very important, there are few researches on the safety analysis of IMA.Aiming at above problems, this thesis makes the following works:Firstly, in this thesis, we study the systems theory model and the characteristics of chain-of-failure model. We compare the difference between the method of hazard analysis based on the systems theory and the traditional hazard analysis method. Safety is regarded as a kind of system property, and safety analysis method based on systems theory can be used to find more risk factors in IMA.Secondly, the existing STAMP models mostly use natural language to describe the system model, while accuracy of the model is easy to be affected by the ability of the analysis. In this thesis, an object constraint language and the UML model are used to describe the STAMP model strictly.Finally, this thesis proposes a hierarchical safety analysis method for IMA platform application system, which decomposes the safety constraint in the design of the IMA application system to both the IMA platform components and application components, providing an accurate safety requirements for IMA platform designer and application developers. Besides, we present a safety analysis and verification method based on STPA as well as model checking. Experimental results show that systems theory and STPA perform more effectively to analyze the safety of IMA.