Abstract: The airborne software is a typical safety-critical software,and its development and verification process is strictly regulated in the aviation industry.The complexity and diversity of airborne software make requirements analysis a crucial area of research.Particularly during the requirements verification phase,it is essential to focus on the interaction patterns between system components and whether the dependencies between variables meet expectations.Therefore,This paper proposes a coupling analysis method based on the VRM model for airborne software requirements,which defines the dependencies between variables in the requirements,and measures the data coupling and control coupling between system components through metrics.In order to solve the deficiencies of the coupling analysis technique based on the requirement level,this paper uses the VRM model as a formal requirement model to model and analyze the system requirements at the system requirement level,which effectively supports the relevant requirements of DO-178C for data coupling,control coupling and software components.Secondly,this paper proposes a coupling measurement method based on the hierarchical dependency relationship between variables,defines the relationship between variables as an n-forked dependency tree structure,and uses a series of algorithms to classify the weights of the variables to measure the coupling degree by constructing variable matrices,demand variable dependency trees,etc.,which forms a prototype for analyzing the data and control coupling based on the dependency relationship of the variables.The research in this paper breaks through the coupling analysis technology based on the requirement level,which provides help for the design of complex systems and improves the quality and reliability of airborne software development.

Key words: VRM modeling, Data coupling, Control coupling, Demand variable dependency trees