Towards Enhancement of Fault Traceability Among Multiple Hazard Analyses in Cyber-Physical Systems

Abstract

When defects in safety-critical systems are exposed to actual mishaps, this can lead to property loss, injury, and/or death. Therefore, safety analysis should be performed to identify and minimize potential faults at the design phase of the software development life cycle. However, cyber-physical systems, in which multiple systems are interconnected by the network, may still pose potential risks because the composite analysis of cyber-physical systems is yet to be addressed; even though the hazard analysis for a single system is performed but it is insufficient to analyze hazards for cyber-physical systems. This paper presents an approach to support fault traceability by identifying content relationships among applied hazard analysis techniques to a cyber-physical system. The applied analysis techniques are Fault Tree Analysis, Event Tree Analysis, and Failure Mode and Effect Analysis. In this work, the relationships among these hazard analysis techniques are identified, and a Fault Traceability Graph is designed to represent the relationship among them. Our proposed approach enables to determine the propagation scope of a fault in order to find the source of a fault. Lastly, we propose a Fault Traceability Matrix to trace the faults and to make sure that all faults are controlled by the safety guards. As a result, we can effectively manage and control the faults at the design phase of the cyber-physical system to ensure the development of a safe system. We applied our proposed approach to Automatic Incident Detection System a real case study to show its validity and applicability.