SPFM (>99%), LFM (>90%), and PMHF (<10 FIT): Calculating Hardware Metrics for ASIL-D

ISO 26262 Part 5 mandates strict quantitative architectural metrics for electronic hardware targeting Automotive Safety Integrity Level D (ASIL-D):

1. Single-Point Fault Metric (SPFM ≥ 99%): Measures the proportion of faults that directly lead to a violation of a safety goal that are detected and mitigated by internal safety mechanisms. 2. Latent Fault Metric (LFM ≥ 90%): Measures the coverage of multiple-point faults that do not directly cause a violation but could combine with a subsequent fault to cause a failure. 3. Probabilistic Metric for random Hardware Failures (PMHF < 10 FIT): Quantifies the residual random failure probability per operating hour, where 1 FIT equals 1 failure per 10^9 hours.

Safe ECU integrates automated FMEDA (Failure Modes, Effects, and Diagnostic Analysis) tools that ingest component failure rate databases (IEC 62380 / SN 29500), verifying compliance across thousands of electronic components.