Waterfall Model OR Classical Waterfall Model:
• Waterfall model is a simplest model of software development paradigm.
• All the phases of sdlc will function one after in linear manner. That is, when the first phase is finished then only the second phase will start and so on.
The Waterfall model was first process model to be introduce and also called "Linear- Sequential Life Cycle Model.
This type of model is basically used for the project which is small and there are "No Uncertain Requirements".
At the end of a phase, a review take place to determine if the project is on the right path and whether or not to continue or discard the project.
In this testing starts only after the development is completed and phases do not overlap.
Advantages of WaterFall Model:
1) Discipline: This staged development cycle enforces discipline. Every phase has a start and end point, and progress can be conclusively identified( through the use of milestones) by both vendor and client.
2) minimal wastage:- the emphasis on requirement and design before writing a single line of code ensure minimal wastage of time and efforts and reduces the risk of schedule slippage.
3) improves quality:- It is much easier to catch and correct possible flows at the design stage then at the testing stage after all the component have been integrated and tracking down specific error is more complex.
Disadvantages of WaterFall Model:
Uncertain Nature of Customer Needs:- due to this estimating time and costs with any degree of accuracy(as the model subjects) is often extremely difficult.
Implicit Assumption to Roadblock: Implicit assumption that designs can be feasibly translated into real products, they sometimes runs into roadblock when developer begin implementation.
No Good Model: Not a good model for Complex and object oriented project as world changing fast as technology changes.
• It haas High amount of risk and uncertainty.
• It is somewhere poor model for long and ongoing projects.
• It is Not suitable for the projects where requirements are at a moderate to higher risk of changing.