解剖FMEDA-汽车电子咖啡厅.pdfVIP

FMEDA Technical Dissection Luo Zhengfa Functional Safety Engineer Hardware Engineer Content 1 Safety Analysis Methods Introduction 2 How to get failure rate of hardware part 3 How to deal with MCU’s failure rate 4 Ten Steps for FMEDA 5 Ground Rules for FMEDA 6 Using Safety Mechanisms in ISO26262 7 Hardware Safety Case Sharing Safety Analysis Methods Introduction Classification : ○Qualitative ○Quantitative ○ Deductive ○ Inductive For Functional Safety: ○ HARA (Hazard Analysis and Risk Assessment) ○ FTA (Fault Tree Analysis) ○ FMEA (Failure Mode and Effects Analysis) ○ FMEDA (Failure Modes Effects and Diagnostics Analysis) ○ DFA (Dependent Failure Analysis) ○ DRBFM (Design Review Based on Failure Modes) Safety Analysis Methods Introduction FMEDA is a quantitative approach, and begins from every failure mode of each hardware part (inductive analysis) Safety Analysis Methods Introduction Hardware Metrics in ISO26262: ○SPFM ○ LFM (Part5,Relative) ○ PMHF (Part10,Absolute) Different ASIL level have different requirements for the metrics Metrics ASIL B ASIL C ASIL D ○SPFM = SPFM 90% 97% 99% LFM 60% 80% 90% PMHF 100 FIT 100 FIT 10 FIT ○ LFM = ○ PMHF = How to Get Failure Rate ISO26262-5 8.4.3 Defines the Source ○ using a recognised industry source ○ using statistics based on field returns or tests ○ using expert judgement But, SN29500 and Birolini are commonly used in German auto parts industry How to Get Failure Rate SN29500 Reliability Prediction ○ For failure rate of transistors: ○SN29500 provide a reference failure rate under the specified conditions ○SN29500 also tell you what factors will affect its fa