Architectural metrics calculation – an efficient approach

According to the ISO26262 [1], the random hardware failures represent all the failures, which, for electronic parts, can occur at any time without any determined cause. These failures follow a probabilistic distribution, and the failure rates can be determined with the help of reliability handbooks, such as IEC62380 or SN29500. Based on the random hardware failure rates calculation, the ISO26262 [1] defines the Single Point Fault Metric (SPFM) and the Latent Fault Metric (LFM) as criteria for architecture: The calculation of the SPFM and the LFM is defined for a bottom-up approach. In this paper, we will provide a simplified method to calculate the SPFM and LFM. The Valeo simplified method enables to efficiently calculate the architectural metrics without going down to hardware parts level. This enables time savings and increased scalability of the safety analyses. We will demonstrate that this simplified method is a conservative calculation while keeping state-of-the-art design level.