Re: [SystemSafety] SIL ratings to be scrapped?

From: SPRIGGS, John J < >
Date: Thu, 22 Aug 2013 08:14:24 +0000

I seem to spend most of my time refuting things like this, but in my own industry segment, which has been beset with a load of new laws. People appear to make up stories about what is now mandatory and go round telling everyone. You see a misconception in a supplier document, you think it a local error and put in a corrective review comment then, the following week, it turns up somewhere else. The current one doing the rounds is, "We must use the software development lifecycle EUROCAE ED-153 for software assurance, because it is going to become mandatory soon". No it is not, but one organisation is going around telling everyone who will listen that it is an "acceptable means of compliance" - it may be acceptable to them, but the competent authorities who have to accept assurance before a system goes into service think otherwise. It can be very costly to present assurance to a Regulator saying that you have used an acceptable means of compliance about which the Regulator has actually published criticism. I find the best strategy is to ask the rumour-monger for evidence; often the evidence will be a vague statement in a guidance document or journalistic piece, but usually none can be found.


From: systemsafety-bounces_at_xxxxxx Sent: 21 August 2013 15:26
To: 'Bielefield Safety List'
Subject: [SystemSafety] SIL ratings to be scrapped?

Hi all,

I have just been taking to one of my customers who do control systems for industrial systems. They have been told by someone they are doing a system for that SIL ratings will "soon be scrapped". Apparently "It will be replaced by ALARP". This seems like a completely misunderstood half a message. Though usually on this sort of thing there is a grain of reality (if miss reported or miss represented) in there somewhere.

I know I have not been paying attention over the summer but I haven't seen anything. Is there a move on any standard to change from SIL ratings for projects?



Eur Ing Chris Hills BSc CEng MIET MBCS FRGS FRSA Technical Specialist Phaedrus Systems Ltd Tel: FREEphone 0808 1800 358 Vat GB860621831 Co Reg #04120771
Http://<> chills_at_xxxxxx

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systemsafety_at_xxxxxx Received on Thu Aug 22 2013 - 10:14:42 CEST

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