What is Waterfall Model in Software Engineering?

What is SDLC:

The system development life cycle also referred to as the application development life cycle is a term used in system engineering, information engineering and software engineering to describe a process for planning, creating, testing and deploying an information system.

Waterfall Approach/ Waterfall Model:

Water fall approach is a basic model of system development. This model follows a flow of step begging from feasibility check up to system maintenance in a sequence order.

This method is also called Linear Sequential method. The step in waterfall model show above in figure.

1.  1.Feasibility Study:

this step used to check technical and financial feasibility check about system development.

      2.Requirement:

Gathering knowledge about the required system developing the specification needed.

     3.Design:

all the functionality converted into graphical form.

     4.Coding:

coding is a process of developing the program for the required system.

     5. Testing:

Insuring that system performance according to user requirement and also check error.
There are two approaches
  i.     Alpha Testing: it is perform at developer end to check the system functionality.
  ii.    Beta Testing: in beta testing, testing perform at end user side. 

     6. Maintenance:

this phase is used to corrects and upgrade system.

Disadvantage of waterfall model:

   1.       If any modification need in design phase they we can’t move back or can’t change in model (modification not allows).

  2.       Not support feasible system.