Famous Failures: The Vasa

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Famous FailuresThe Vasa
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The Story of the VasaTaken from
http//www.cise.ufl.edu/jnw/OOCourse/Lectures/01.
05.html

• 1625 King Gustav of Sweden commissions
  construction of a new flagship, the Vasa.
• Hendrick Hybertszoon (master shipwright from
  Holland) is selected to build it.
• No written specifications
• Shipbuilder assumes ship will be 108 feet in
  length.
• After first review, King Gustav requests a 135
  foot ship.
• Timber is added to make the ship 120 feet.
• While on vacation, King Gustav finds out that the
  Danish king is building a ship with three gun
  decks.
• He asks that a third gun deck be added to the two
  already on the Vasa.
• 50 brass 24-lb cannons (at one ton each) will be
  added.
• Stability tests are conducted (involving 30
  sailors who run from one side of the ship to the
  other). The ship appears to be unstable, but the
  problems are ignored and not communicated up the
  chain.
• On a Sunday in August 1628, the Vasa sets sail.
  One mile from harbor a wind gust catches the main
  sail and the ship overturns and immediately
  sinks.
• The Vasa was later brought up from the briny deep
  at greater cost than was expended in her
  manufacture.

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Parallels between Shipbuilding in the 1600's and
Software in the 1990's

• Shipbuilding in the 1600's was a craft based on
  engineering practice.
• Specifications for ships were ad hoc and usually
  verbally communicated.
• Designs for ships were inadequate to insure the
  finished product would satisfy the needs of its
  users.
• The full implications of changes to the design
  were not always understood.
• Too much time was wasted carving decorative
  sculpture prior to determining if the ship would
  sail.
• Success breeds failure. Those who succeeded in
  building small ships would believe they knew how
  to do it even though they had no idea of the
  fundamental physical principles involved.
• Shipwrights in the 1600's (one in particular) did
  not know how to say no'' to customers.

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Implications

• Systems may last longer than we think (sometimes
  hundreds of years).
• Maintenance costs may exceed the original
  development cost.
• We can examine, in minute detail, components of
  systems we have built decades or even centuries
  later.

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Famous System Failures 1 Famous System Failures 1 Famous System Failures 1 Famous System Failures 1 Famous System Failures 1
Name Year poor requirements? Probable cause of failure
Hubble Space Telescope 1990 No Lack of total system test. Mirror was too flat on one edge by 1 / 50th of the width of human hair.
Ariane 5 missile 1996 No Incorrect reuse of software Faulty scaling up, Faulty software testing, Software operand error
SuperConducting SuperCollider 1995 No Cost overruns, Failure to maintain public support
GE rotary compressor refrigerator 1986 No Inadequate testing of new technology
Motorola, Iridium 1999 No Misjudged competition and miss-predicted technology
IBM PCjr 1983 Yes An attempt to impose customer needs
Space Shuttle Challenger 1986 No Failure to communicate with design, Motivation to make client happy
War in Vietnam 1967-72 Yes No problem statement, Micromanagement
Edsel automobile 1958 Yes Failure to discover customer needs
Titanic 1912 No Poor quality control
Apollo-13 1970 No
http//tucson.sie.arizona.edu/sysengr/slides/failu
res.doc.
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Famous System Failures 2 Famous System Failures 2 Famous System Failures 2 Famous System Failures 2 Famous System Failures 2
Name Year poor requirements? Probable cause of failure
Tacoma Narrows Bridge 1940 No Scaling up an old design (remind you of something?)
New Coke 1988 Yes Arrogance, The wrong question questionnaire, Underestimating the effects of social influence
A-12 airplane 1980s No Mismanagement (2B for nothing)
Chernobyl Nuclear Power Plant 1986 No Bad design, Bad risk management, Cost cutting
Lewis Spacecraft 1997 No Design mistakes, Ineffective assurance processes at NASA
Mars Climate Orbiter 1999 No Lack of training of Navigation team, Technical error (use of English and not Metric units)
Mars Polar Lander 2000 No Failure of middle management
Sept 11 attack on WTT 2001 Yes Flimsy cockpit door
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Super-Conducting Super-Collider Failure

• In the 1980s a project got underway in the U.S.
  to build a device in Texas.
• It had the support of 3 presidents from both
  parties Reagan, Bush (senior), and Clinton.
• Billions were spent on research and development
• Land for the 'runway' was purchased and
  excavation begun.
• And then Congress pulled the plug.
• back

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Challenger

• On January 28, 1986 the challenger space shuttle
  exploded about 1 minute after launch killing all
  7 astronauts on board.
• The shuttle exploded because two rubber O-rings
  leaked after losing their resiliency because the
  shuttle was launched on a very cold day (less
  than 0 Celsius).
• On the day before the launch the engineers who
  designed the rockets were opposed to launching
  the challenger because they were concerned that
  the rings would not seal at such cold
  temperatures. ?This was to be the EXACT cause of
  the accident.

Back
Edward R. Tufte Visual Explanations.
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Challenger

• The engineers presented their case using 13
  charts which they faxed to NASA.
• A high level NASA official was appalled by the
  recommendation, and asked that the rocket maker
  (Morton Thiokol) should reconsider even though
  this was the ONLY no-launch recommendation in 12
  years.
• Other NASA officials pointed out serious
  weaknesses in the charts.
• Reassessing their the situation after such
  responses, the Morton Thiokol managers changed
  their minds and favored a launch.
• They explained their change of mind by saying
  that the evidence presented by the engineers was
  inconclusive in showing that O-ring problems were
  linked to cool temperatures.

Back
Edward R. Tufte Visual Explanations.
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Challenger
Back
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Challenger
Back
Edward R. Tufte Visual Explanations.
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Tacoma Narrows BridgeCollapsed in 1940

• If engineers like had solved the same problem
  nearly a century ago- why did it happen?
• Two reasonsBy the 1920s and 1930s, after
• many successful suspension bridges had been built
  
• engineers became overly confident in their
  ability to extrapolate from earlier experience
• Preoccupation with with economy and aesthetics

See movie
Back
http//www.cis.gsu.edu/mkeil/cis8150/why20study
20failure.pdf
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Why Study Failures?

• There is probably more to learn from failures
  than from successes
• As long as you are willing to look honestly at
  the reasons for failure
• Too many times failures are brushed away and not
  learned from- ensuring that more failures will
  occur
• ? Those who do not remember the
• past are condemned to repeat it