WATER FALL MODEL

waterfall model:

  water fall model is a sequential design process in which progress is downward
  the phases are analysis ,design coding testing, implementation.In this model one can move to the next phase when the previous phase  is completed . Here the process is downward like water fall so it is called waterfall model. let describe the phases 
 1.ANALYSIS :
 In this phase we analyize the system, requirement is gathered and discus them time shedule is prepared in this phase .BRS(business requirment specification) is prepared in this phase.After that we move to the next phase 
2 DESIGN :
In this phase the UI screens are designed.FRS is prepared and the back end is designed.
3 CODING:
In this phase the actual programming code is written.The purpose of coding to prepare a programme which performs the specific function.tables in database are created.
4 TESTING:
after the coding is finished we move to the next phase where we test the whole software or application.If any error found we refer it to the developer for correction. Here we check the  software is made as per the requirement or not
IMPLEMENTATION:
Here the software is deployed at the clients end and the software is maintained.
ADVANTAGES:
1.IF there is a fault or requirement in the project it is detected at the initial phases .
2 Strong documentation is available.
 DISADVANTAGES 
 1 Huge amount of time is wasted because it is a sequential process
 2.we cant modify the requirement once the  process is started.
 3.Testing  phase comes quite late