Why Arent Computers Reliable

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Why Arent Computers Reliable?

• By Adam Lewis

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Causes for Computer Errors

• Faulty Design
• Incompatible systems
• November 26, 2004, a bad update to U.K. Dept. of
  Work and Pension which handles benefits for 24
  million residents
• Sloppy Implementation
• Runtime values exceed the range of variable data
  types
• Patriot missile failure during gulf war killed
  26 caused by truncating a time variable
• Poorly Trained Users
• An outside user changed houses value to 400
  million blamed for budget shortfalls and possible
  layoffs Indiana

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Severity of Errors

• Number of people inconvenienced
• Economic impact to a business or private entities
• Loss of profit/inventory/customers
• Lawsuits from customers
• Number of lives that are jeopardized

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Service Interruptions

• Communication Phone, Internet, TV and Radio
• In 2005, an update with internet backbone Level
  3s computers caused much of the internet to
  become inaccessible
• Utilities Nuclear Power Plants and Power Grid
  Control
• Northeast blackout in 2004
• Transportation Traffic Lights, Subways, Railway
  Coordination and Air Traffic Control

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Medical

• Diagnostics and Life Support Systems
• Treatment Equipment
• Therac-25 incident
• Due to software error and human negligence, the
  machine overdosed 6 patients with radiation. 3 of
  those patients died from their treatments
• Leading cause was the user interface didnt
  require the operators to verify radiation dosages

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Data Entry Errors

• Financial Institutions Stock Trading, Banks and
  Credit Bureaus
• Monthly credit card bill asking man to pay his
  balance of 0.00. When he wrote a check for that
  amount, it crashed his banks computers
• Businesses Membership, Billing, Inventory and
  Payroll
• A woman was billed 6.3 million for her
  electricity bill because of input error
• Tax and Census Databases
• In 1993, IRS modified software to not bill
  Midwest flood victims, but the change caused
  thousands of erroneous bills to be generated.
  Some were in the billions of dollars
• Medical Records
• Requires extensive user training and still prone
  to input errors

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Data Entry Errors Continued

• Birth and Death Records
• A woman was denied her social security payment
  because she was listed as Deceased in the
  social security computer
• Education
• An error in the grading system at McGraw-Hill
  company caused many principles and
  superintendents to be fired and 9000 students
  were mistakenly required to attend summer school

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Sources

• Patriot Missile Failure http//www.resonancepub.co
  m/oops.htm
• Indiana House Wrongly Valued http//news.yahoo.com
  /s/ap/20060211/ap_on_fe_st/misvalued_house
• Credit Card Computer Error http//www.ece.tntech.e
  du/Humor/StupidComputerError.htm