-----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Alex UMX Sent: Thursday, November 19, 2009 11:34 AM To: IBM-MAIN@bama.ua.edu Subject: Re: Check out Computer glitch to cause flight delays across U.S. - Mar ketWatch
Well, 99.999% reliability means that 1/10000 of the time the thing is not reliable = about 8 hours per year. Not to confuse with z/VM reliability that was 99.999999 if I recall it correctly back in 1991 or so for VM/ESA 1.0. <SNIP> Let me try to put this into some perspective. This is the flight plan system. Its failure means that flight plans must be entered by FAA personnel manually. Let us look at ATC reliability. If ATC were to have a 99.9% reliability at Chicago O'Hare -- 1 fatal accident per hour. 99.999 was 1 per month. I attended an FAA presentation where they were putting the percentages of reliability into terms that had meaning for the average person (in that presentation, the average person was a licensed pilot). Regards, Steve Thompson -- Opinions expressed are those of the poster and may not reflect those of poster's employer -- ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
