Waterfall Model 

Waterfall Model : 

The first SDLC methodology to take hold in software development was the Waterfall method. Associated with Winston W. Royce, It was first introduced in a paper he wrote and used it as an example of what a bad methodology looks like: "I believe in this concept, but the implementation described above is risky and invites failure." Despite his warnings and guidance, the Waterfall methodology quickly became the standard and stayed that way for over 20 years.


The waterfall model is the oldest of all SDLC methodologies. It’s linear and straightforward and requires development teams to finish one phase of the project completely before moving on to the next.

Each stage has a separate project plan and takes information from the previous stage to avoid similar issues (if encountered). However, it is vulnerable to early delays and can lead to big problems arising for development teams later down the road.



Waterfall is broken down into phases, and other modern methodologies can even pull from these phases and utilize them, these phases are:

  1. Requirement analysis / Collection
  2. Feasibility / Planning analysis
  3. Architectural Design
  4. Software Development
  5. Testing
  6. Installation / Deployment
  7. Maintenance  

Disadvantages of waterfall model: 

1   1..Customers can not asked for the changes again and again in the SRS.
2.     Back tracking is very difficult in waterfall model.
3.     Coding and testing both are done by the developers.

 

Advantages of waterfall model:

1.     Since the SRS is freeze we get a stable software produce in the end.

2.     Investment is less.

 

Application:

  1. We used this model for simple projects and short term projects.
  2. When the customer does not ask for any changes in SRS Waterfall model is used.