Waterfall Model

                                                Waterfall Model

It is the quiet , earliest and often extensively used operation model. In this dummy, each stage of the life cycle is concluded ahead the commencement of a new aspect . It is indeed the first engineering entrance of software development.

The waterfall model furnish a methodical and subsequent approach to software development. But, in this model, exhaustive regiments should be applicable at the time of commencement of the scheme , but in definite custom, the regiments keep on originating during different phases. The water fall model can accommodate the new requirements only in maintenance phase . Immensely, it does not incorporate any variety of exposure judgement. In waterfall model, a working model of software is not convenient. 

Advantages of waterfall model :

• Waterfall model is a simple and easy to understand and use.
• It is apparent to conduct due to the rapidity of the model 
• Each phase has specific review process.
• In this model aspect are handled and built one at a time. Phases do not overlay.
• Waterfall model works well for smaller projects .
• In this model requirements are clearly defined and very well understood

Disadvantage of waterfall model :

• In this model we can't go back in each and every phase
• Making changes in this model becomes difficult because we can't go back 
• The amount of risk and uncertainty is high 
• Poor model for big projects 
• There is less customer involvement.

Where to use waterfall model :

• Requirements are well defined and well known
• Project must be small
• Product definition is stable