The Fault Tree Analysis appears to be a decent tool for determining safety concerns with a fully compliant listed/certified product, because it makes the team address things like multiple fault scenarios and foreseeable misuse. It is subjective in nature, because many assumptions need to be made about the probability of an event happening, so it requires some conservative thinking when working with terminology like "improbable", "inconceivable", "known to happen", etc.
e.g. a Y-cap shorts & chassis is left ungrounded & user touches chassis (assign an approximate probability to each one of those and you get an idea of how the fault tree is assembled) It can be a real "eye-opener" _______________________________________________________________________________ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: John Woodgate <j...@jmwa.demon.co.uk> To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 12/07/2012 08:21 AM Subject: Re: [PSES] The Cost of Safety In message <000c01cdd486$cdf05bc0$69d11340$@ieee.org>, dated Fri, 7 Dec 2012, Jack Burns <jbu...@ieee.org> writes: >Should the added cost of the safety features be considered a marketing >or legal expense? Well, either, because generally for those budgets USD50000 is a trifle, whereas it's half the annual R&D budget.(;-) >Also, I have had marketing try to dictate a less safe product because >they wanted it cheaper, or didn?t want all those distracting labels, or >didn?t want those ugly warnings in their pretty manuals, or worse, >didn?t want to imply that there were any hazards with the product. I've used that 'Do you have so many customers that you can afford to kill a few?' response to that. It doesn't make one popular but it gets the point over. -- OOO - Own Opinions Only. See www.jmwa.demon.co.uk The longer it takes to make a point, the more obtuse it proves to be. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. ______________________________________________________________________ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
