A New Design Review Method for Functional Safety of Automotive Electrical Systems

Abstract

For an automotive electrical system design review, FMEA can be used to exam what would happen when any wire in the circuit goes open circuit, shorts to ground or shorts to battery, or when any components fail in expected ways. However, traditional FMEA method has some inherent disadvantages as criticized by many researchers. Besides, it is less expensive and far more effective to build in functional safety early in the design stage than try to tack it in the later implementation or operation stage. Thus the main purpose of this study was to propose a new design review method to link DRBFM with vague set based FMEA for recovering traditional FMEA's inherent problems, helping to evaluate, prioritize and prevent automotive electrical systems' failure modes caused by design change. In the first stage, a DRBFM was taken to identify failure modes and capture their causes and effects information needed for subsequent FMEA scoring process. In the second stage, a vague set based FMEA provided a quantitative analysis method to quantify the design discussion and review procedure under uncertain and vague environment. Obtained the quantitative data, a pattern recognition procedure for recognizing action priorities of failure modes was conducted in the third stage. Finally, a numerical example was conducted to demonstrate that the proposed design review method is effective and efficient for continuous improvement of failure modes due to design change of automotive electrical systems.