In message <201048ea81ba0745aca78e4cc8839001769...@desmdswms201.des.grplnk.net>, dated Thu, 18 Jan 2007, "Haynes, Tim (SELEX) (UK Capability Green)" <tim.hay...@selex-sas.com> writes >Outside the field of standards - if I assess that the chance of a >hypothetical product causing a death is, say, one in a million per >annum then there is a million-to-one chance (1x10e-6) of a product >related death in one year of operation. I assume that that risk is >acceptable. > >If I sell 100 million units and they have a life of 10 years, it would >seem that there is a chance that 1000 people being killed as a result >of this hypothetical product. > >The general risk of death (in the UK) in all the population from all >causes is just less than 1 in 100 (1 in 88 was the last number I saw >quoted), so a risk of 1 in 1 million would be very a small risk. > >But 1000 people dead in 10 years seems a lot of people - so... > >What is the flaw in the logic please?
There is no flaw. 1 in 1 million is just not improbable enough. 1 in 10 million is about right for seriously hazardous failures, if only for the practical reason that it's almost impossible to measure a lower probability, but not all of those would actually result in a death. Maybe only 1% would; that needs to be looked at on a case-by-case basis. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk There are benefits from being irrational - just ask the square root of 2. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.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...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
