Waterfall Process Model

The Waterfall Model is one of the most important types of plan driven software engineering approach. The Waterfall Model is one of debilitated model that includes following steps 

Steps of Waterfall Model 

Requirement Gathering

In this step, we design our plan and according to that plan, we specify our requirements. What are our goals and what are our constraints. This is not an easy step. It requires a lot of attention and devotion. After having complete  analysis, we specify our requirements

Software/System Design

This step deals with an identification of system design based on initial requirement gathering. This phase is very important. The software/system design should completely reflect the requirements of the system. 

Coding & Unit Testing

 In this step, programmer writes a code based on proposed design. Each module of the system will be tested individually. For example, Admission and attendance system are two different modules of the student portal. The progammers write code of each module and each module will be tested individually. 

System Testing

 All modules are integrated and then tested to make sure that system is working as per defined standards 

Deployment

 The system is deployed in the practical  environment and then tested to make sure that it is working as per requirements or not. 

Condition when to use Waterfall Model

1.   when requirements are understood
2.   When our requirements are fixed and unambiguous

Alternatives of waterfall

The alternatives of waterfall include rapid prototyping that furnish user participation in early stages or to cater those functionalities of system that emerges. In rapid prototyping, all the specifications are being taken and we delicately go through that specifications. Moreover, in prototyping, we can redefine the requirements with changing requirements. 

 Pros of waterfall model

• Waterfall model is very simple model
• Stages are well-defined 
• Documentation of waterfall is available  

 Cons of waterfall model

•  Waterfall model does not cater changing requirements
•  Percentage of  precarious errors is very much high
•  Waterfall model is not suitable for sophisticated software.
• Costly