{"id":5643,"date":"2021-09-30T10:10:45","date_gmt":"2021-09-30T08:10:45","guid":{"rendered":"https:\/\/lorit-consultancy.com\/en\/?p=5643"},"modified":"2024-02-08T12:28:26","modified_gmt":"2024-02-08T11:28:26","slug":"sos-safety-over-sectors-i-will-survive","status":"publish","type":"post","link":"https:\/\/lorit-consultancy.com\/en\/2021\/09\/sos-safety-over-sectors-i-will-survive\/","title":{"rendered":"SOS \u2013 Safety over Sectors \u2013 I will survive"},"content":{"rendered":"\n

At first I was afraid, I was petrified\u2026 That was my initial reaction when I encountered functional safety<\/strong>. First, there was talk about IEC\u00a061508<\/strong> certification, the \u201cmother of all safety standards\u201d. No big deal for a new safety officer like myself \u2014 or so I thought. One tiny detail was revealed during the project, namely that the products were also going to be marketed in the USA. Hold on, they don\u2019t even use IEC\u00a061508? Excuse me? UL\u00a01998<\/strong> and UL\u00a0991<\/strong>? Well, okay, the standards won\u2019t be that different; the priority is still functional safety. And while I was preoccupied with the UL standards, we received an order to make preparations for having our product certified under ISO\u00a013849<\/strong> for a customer\u2026 To keep it short, this was followed by ISO\u00a026262<\/a><\/strong>, EN\u00a050126\/8<\/strong> and IEC\u00a061010<\/a>\/60601<\/a><\/strong>, and others. What did they even have in common? As a matter of interest, I then also conducted UL\/IEC\u00a060730<\/strong>, IEC\u00a062061<\/strong> and IEC\u00a061511<\/strong>.<\/p>\n\n\n\n

In this blog post, I hope to shed a little light on this seemingly endless expanse of standards.<\/p>\n\n\n\n

First, here is an overview of the standards\u2019 names:<\/p>\n\n\n\n

IEC 61508<\/td>Functional Safety of Electrical\/Electronic\/Programmable Electronic Safety-related Systems (E\/E\/PE, or E\/E\/PES)<\/td><\/tr>
UL 1998<\/td>Standard for Software in Programmable Components<\/td><\/tr>
UL 991<\/td>Standard for Tests for Safety-Related Controls Employing Solid-State Devices<\/td><\/tr>
ISO 13849<\/td>General principles for design, provides safety requirements and guidance on the principles of design and integration of safety-related parts of control systems (hardware or software)<\/td><\/tr>
ISO 26262<\/td>Road vehicles \u2013 Functional safety<\/td><\/tr>
EN 50126<\/td>Railway Applications \u2013 The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS)<\/td><\/tr>
EN 50128<\/td>Railway applications \u2013 Communication, signalling and processing systems \u2013 Software for railway control and protection systems<\/td><\/tr>
IEC 61010<\/td>Safety requirements for electrical equipment for measurement, control, and laboratory use<\/td><\/tr>
IEC 60601<\/td>Medical electrical equipment- General requirements for basic safety and essential performance<\/td><\/tr>
IEC\/UL 60730<\/td>Automatic electrical controls for household and similar use<\/td><\/tr>
IEC 62061<\/td>Safety of machinery \u2013 Functional safety of safety-related electrical, electronic and programmable electronic control systems<\/td><\/tr>
IEC 61511<\/td>Functional safety \u2013 Safety instrumented systems for the process industry sector<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

So you can say that I\u2019ve gained a certain overview of the various topics they cover in the meantime. However, I would also like to note that there are countless other standards concerning functional safety that I have not yet worked with.<\/p>\n\n\n\n

Fundamental goals of all standards<\/strong><\/h2>\n\n\n\n

In any event, I have since come back to my original opinion. That the standards essentially have the same structure and goals. Some standards make reference to others and attest to their integrity, or refer to other standards (example: ISO 13849 accepts the results of a development based on IEC 62061, or refers to the software portion of IEC 61508). Yet, the procedure<\/strong> always remains the same:<\/p>\n\n\n\n

    \n
  1. Describe your product
    a) What is the intended use?
    b) What are the limits?<\/li>\n\n\n\n
  2. What can go wrong?
    a) Due to defects in the device \u2013 random failures
    b) Due to faulty production \u2013 systematic failures
    c) Due to improper use \u2013 foreseeable misuse<\/li>\n\n\n\n
  3. What\u2019s the worst that can happen?<\/li>\n\n\n\n
  4. How can that be counteracted?<\/li>\n\n\n\n
  5. Are the risk alleviation measures sufficient?<\/li>\n<\/ol>\n\n\n\n

    In summary identify and mitigate hazards.<\/p>\n\n\n\n

    <\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    The difference lies in the detail<\/strong><\/h2>\n\n\n\n
    \n
    \n

    The \u201cbeauty\u201d of it is that different expressions are used in each case. If the summary of risks to be avoided is referred to as the \u201cFunctional Safety Concept\u201d in the automotive world, one will not find a work product for this in IEC 61508, but rather a description thereof in the chapter titled \u201cRequirements to the complete system\u201d. But terms that deal with the likelihood of failures are also not uniform. In the rail industry, this is TFFR (\u201cTolerable Functional Failure Rate\u201d); in IEC 61508, it is PFH (\u201cProbable Failure Per Hour\u201d (for high-demand systems \u2014 for low-demand, it is PFD, \u201cProbable Failure on Demand\u201d)); and ISO 26262 contains PMHF (\u201cProbabilistic Metric for Random Hardware Failures\u201d), while ISO 13849 simply uses MTTF (\u201cMean Time to Failure\u201d \u2013 i.e. the inverse of the likelihood of failure). Essentially, it\u2019s a dissemination of language as was the case at the Tower of Babel\u2026<\/p>\n<\/div>\n\n\n\n

    \n
    \"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n

    Benefits across industries<\/strong><\/h2>\n\n\n\n

    However, I recommend that everyone read through other industries\u2019 standards. There is no optimal standard that explains everything completely and comprehensibly. For example, the medical device standards provide pragmatic guidance on defining intended use<\/strong>, while the automotive industry offers a clear list of work products<\/strong> that should be produced. The original standard IEC 61508, with its generic structure, provides a rich portfolio of various verification and validation methods<\/strong>.<\/p>\n\n\n\n

    In short: each additional standard gives a better insight into the world of functional safety and the opportunities that one can \u201crealistically realise\u201d in their own projects. Admittedly, this takes time and requires someone who likes to learn from other industries.<\/p>\n\n\n\n

    <\/p>\n\n\n\n

    By Gerrit Stein\u00f6cker – Functional Safety Consultant<\/p>\n","protected":false},"excerpt":{"rendered":"

    At first I was afraid, I was petrified\u2026 That was my initial reaction when I encountered functional safety. First, there was talk about IEC\u00a061508 certification, the \u201cmother of all safety standards\u201d. No big deal for a new safety officer like myself \u2014 or so I thought. One tiny detail was revealed during the project, namely […]<\/p>\n","protected":false},"author":7,"featured_media":5650,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[9],"tags":[],"class_list":["post-5643","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/posts\/5643","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/comments?post=5643"}],"version-history":[{"count":8,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/posts\/5643\/revisions"}],"predecessor-version":[{"id":7344,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/posts\/5643\/revisions\/7344"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/media\/5650"}],"wp:attachment":[{"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/media?parent=5643"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/categories?post=5643"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lorit-consultancy.com\/en\/wp-json\/wp\/v2\/tags?post=5643"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}