HIERARCHICAL STATE MACHINE MODEL FOR ANALYZING SAFETY HAZARDS IN REAL-TIME SYSTEMS

Real-time systems must avoid hazardous situations. To achieve this, their functionality should be investigated under time constraints. A model based on Hierarchical Communicating Real-time State Machine (H-CRSM) and analysis methodology is proposed in this paper with the objective of obtaining any hazardous events that may occur in the input ANSI-C program. The system outputs a scenario list of the different hazards. A path in the code showing the cause of the undesirable event is associated with each hazardous scenario. The strength of the proposed methodology is that the process of hazardous situation detection does not require the running of the ANSI-C program many times with distinct values for the inputs. It also focuses on analyzing the software level of the life cycle. It is not like most of the verification and analysis tools that check system levels. The system level may be bug-free, but the software level may not be.