Waterfall Model

Waterfall Model

A waterfall model is a sequential process where the outcome of one phase is used as the input for the next phase. Each phase is generally completed before moving on to the next phase. 

When to use a Waterfall Model

A waterfall model is used when a project is short, the product definition is stable, requirements are clear and fixed, technology is not dynamic, and requirements are not ambiguous.



  • Simple to use and understand
  • Each phase has a defined result and process review
  • Separate sequential phases
  • Easy to determine key points in the cycle
  • Easy to classify and prioritize tasks
  • Great for small projects with clear requirements


  • Software is only available at the end of the project
  • High risk and uncertainty
  • Inadequate for complex and object oriented projects
  • Unsuitable for long term projects
  • Progress is hard to measure
  • Implementation at the end prevents identifying problems in advance