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Showing posts with the label Functional safety

ASIL Certification for HW Components and HW Evaluation

In our previous post , we introduced the topic of ASIL certification for HW elements. In this article, we will give you an idea of what is done as part of ASIL Certification. We will then introduce the concept of HW Evaluation , how it is to be done and what are the challenges in doing it.   Note: ISO26262 does not talk about "Certification" and what is the way to "certify" a component.  ASIL Certification means that a component was developed according to ISO26262, it was audited by Independent Safety Auditors and the Auditor confirmed that the Component meets the qualitative and quantitative expectations for that ASIL level. The Idea behind “ASIL Certification” Basics first. How is Safety is achieved in an Item? By sufficiently preventing Systematic failures - by good design and following ASIL development processes By introducing safety mechanisms to detect random hardware failures and achieving the required quantitative Hardware Metrics for that ASIL level.  Let u

Should I use “ASIL certified” HW Components?

Safety beginners are quite often very confused about how Safety affects the hardware design and choice of components in the BOM.  “Should I use ASIL certified Micro controllers, CAN transceivers, PMICs and switches in my ASIL program? What about the resistors and capacitors? Do we even have ASIL certified passives in the market?” they ask. In this blog and next ones to come, we will clear the confusion surrounding “ASIL” certification and qualification of Hardware elements. We will cover several questions surrounding this topic. This blog post will cover the following questions: 1. Background – How the ASIL certification for HW really started 2.Scope of ASIL Certification for HW – Which HW elements are expected to be ASIL Certified and which need not be Background – How the ASIL certification for HW really started It was in the ISO26262-2018 edition, Part 8, Clause 13 “Evaluation of Hardware elements” that for the first time, the idea of “ASIL certified” ICs was introduced. In this cla

Cascading Failures

 

ASIL Operating Systems - Which is your pick?

If you are working in the software of a safety critical product, you are most probably using an ASIL 'certified' Operating system in it.  The market is flooded with various ASIL-certified Operation Systems (OSs) from various Tier 2s. On top of it, several Tier 1s and OEMs themselves are developing their own OS in ASIL compliance. This blog summarizes the ASIL-certified OSs that are available in the market, what features they provide and what do they promise for its users. Disclaimer : We have analyzed only the public literature available for the various OSs and written this article based on what we learnt from them. We do not have working experience in most of these OSs. Hence, we could have missed describing some of the features that are available in these OSs simply because it was not stated in their public literature. We have structured the content of this article as follows: What are the broad expectations of an Operating System from a Functional Safety perspective? What ar

Systematic faults and failures

The ISO26262 provides a bookish definition for Systematic faults and failures. In this post, we have explained our understanding of what these mean. To do so, we have described the following aspects: An easy way to understand systematic faults & systematic failures Possible scenarios in which systematic faults could occur Challenges with complete elimination of systematic failures Probability of systematic failures An easy way to understand systematic faults & systematic failures In simple terms we would like to call Systematic faults as "Method or Process faults”. It is any fault in the way of applying methods or processes whose consequent failure shows up in a deterministic way. This consequent failure is what is called a Systematic failure. What do we mean by "deterministic"? It means that if the same fault is injected into the system 'n' no of times under specific conditions, the same failure will occur every time. The failure is not really tied to th