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Re: [RangeVoting] how common are computer bugs?

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  • Dave Ketchum
    The Yorktown sounds like a special case of software being insensitive to defending against error. Zune reminds us that accidental, or
    Message 1 of 2 , Feb 28, 2010
      The Yorktown sounds like a special case of software being insensitive
      to defending against error.

      "Zune" reminds us that accidental, or accidentally-on-purpose, events
      can avoid happening during testing - and kill us later.

      Anyway, hardware, programmer, and programming language problem
      frequency is somewhat controllable.

      Humans can and do also err. Does not matter exactly what Ed Flynn did
      in the Bronx - DOES matter that that mentality exists and can be
      expected to perform likewise if permitted.

      THEREFORE I suggest using both in combination with intent to minimize
      the likelihood of undetectable/uncorrectable errors.

      Dave Ketchum

      On Feb 28, 2010, at 12:58 AM, WarrenS wrote:

      > Prof. Thomas Huckle (Institut fu:r Informatik, TU Muenchen)
      > gives the following estimates:
      >
      > * Standard Software: 25 bugs per 1000 lines of program.
      > * Good Software: 2 errors per 1000 lines.
      > * Space Shuttle Software: < 1 errors per 10000 lines.
      >
      > Thus he estimates Microsoft Windows-95 (10million lines of program)
      > has 200000
      > bugs, and Handy (Cellular Phone OS) has 200K lines of program and
      > around 600 bugs.
      >
      > Hardware bugs: INTEL believes there were no more than 80-90 Bugs in
      > the Pentium.
      >
      > A few (of many) famous examples include:
      >
      > * Ariane 5 rocket launch 1996 (integer overflow occurred, exception
      > handler disabled/inadequate, hence memory dump, hence rocket
      > explosion, mission destroyed, $370 million loss).
      >
      > * Microsoft "Zune" media players -- thousands of them died on 31 dec
      > 2008.
      > Traced to dumb programming bug that causes troubles only on the last
      > day of a leap year.
      >
      > * USS Yorktown, a 567-foot, 9600 ton warship, was the first US navy
      > "smart ship" which was to be run by microsoft windows NT.
      > On 21 Sept. 1997, a systems administrator fed bad data into the
      > ship's Remote Database Manager, which caused a buffer overflow when
      > the software tried to divide by zero. The overflow crashed computers
      > on the LAN and caused the Yorktown to lose control of its propulsion
      > system, Navy officials said. (Gives a new meaning to "blue screen of
      > death.")
      > The Yorktown shut down totally - no navigation, no engines - and had
      > to be towed into port. So far, software total failures have
      > occurred at least 5 times, each time the Yorktown had to be towed
      > into port. Some news articles claim this happens a large majority
      > of times the Yorktown goes to sea.
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