waterfall models

 

waterfall model phases

• Requirements analysis and definition 
• System and Software design
• Implementation and unit testing
• Integration and system testing 
• Operation and maintenance

The main drawback of the waterfall model is the difficulty of accommodating change after the process is underway. One phase has to be complete before moving onto the next  phase. 

 

 problems

Inflexible partitioning of the project into distinct stages makes it difficult to respond to changing customer requirements.

Therefore, this model is only appropriate when the requirements are well-understood and changes will be fairly limited during the design process.

Few business systems have stable requirements.

The waterfall model is mostly used for large systems engineering projects where a system is developed at several sites.