Waterfall Model assumes ideal world

• Specifications never complete and/or consistent
  • Customer knows current situation, but hard to envision what might be.
  • Customer makes (inadvertent) assumptions
  • Different clients (even within the same organization) may have different visions
  • Examples:
    • North American Anti-ballistic Missile Defense System
    • F-16 landing gear
• First release takes 1-2 years
  • Specifications change as customer's identifies new needs
  • Laws, business climate change
  • Design decisions assume specifications
  • Coding modifications must keep up with changed specifications, design

created April 29, 2003 last revised April 30, 2003

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