Modeling and analysis of IMA inter-partition communication safety requirement based on STPA

Integrated Modular Avionics (IMA) have many advantages, but the characteristics of resource sharing and interaction have brought great challenges to the safety analysis, the traditional safety analysis methods cannot fully capture the safety requirements of IMA, and also not good at analysis and validation for requirements based on formal method. In view of these shortcomings, and based on the system theory process analysis method, we take IMA inter-partition communication as an example object, find out the control and feedback action in the process of inter-partition communication, then construct the control structure model of the inter-partition communication, and derive the unsafe control action, safety constraint and cause. Based on the four-variable model, we establish a formal model of the safety requirements, and use the formal method to analyze and validate the safety requirements rigorously. Through the case study, a feasible safety analysis method is established for the IMA system with resource sharing and complex interaction characteristics.