Waterfall Model - SDLC Models

The waterfall model actually originated from the Manufacturing and Construction Industry.

Father of Waterfall Model    : Winston W. Royce
Year                                    : 1970
Other Name                        : Royce 1970
Mainly used in..                    : IT Industry for SDLC

Each phase is distinct. On completion of one phase, moves on to the next phase. The phases are strictly time sequenced.

Attributes of Waterfall Model:

1) Each phase is distinct and are separated
2) Communication happens only through the pre-specified outputs
3) When error occurs, it is traced back to one previous phase at a time

As stated already in (SDLC) Software Development Life cycle, the project under goes series of phases.

After the requirements collection is done SRS document is generated. This is the input for the Analysis and the Design Phases. At the Design Phase SDD is generated and it becomes the input for the Coding Phase. The developed product is fed as the input for the Testing Phase and so on.


Advantages and Disadvantages:

Advantages:

1) The Waterfall Model is ideal for Life-Critical and Mission-Critical Applications.
2) The Waterfall Model can be used where the requirements are fixed and will not change forever(Eg. Travel Software, Maps etc)
3) The developers can have good managerial control

Disadvantages:

1) The whole product would go wrong, if the Requirements Collection itself is wrong
2) This is a Time consuming process
3) Testing is just a Phase and it is not done throughout the SDLC