Waterfall Model Development Process

Waterfall approach was first SDLC Model to be used widely in Software Engineering to ensure success of the project. As per name suggests “Waterfall”, it means flow of water which goes in one direction. So Waterfall Model is also known as sequential software development process, in which progress is seen as flowing downwards through different phases.

The waterfall model is widely used for most of the commercial software development projects, where each phase has very well defined outputs at the end of every stage and hence monitoring the progress of the project will be very effective.

             

The first formal description of Waterfall Model article was given by Wilson W. Royace in the year 1970, although Royce did not use the term waterfall in that article. Royce presented this model as an example of a flawed, non-working model, which is how the term is generally used in writing about software development process to describe a critical view of a commonly used software development practice.

There is a misconception about the waterfall model is that once the specifications document is written, this document cannot be modified. You can always modify the specifications document but you need to follow a formal process of getting the modification approved by a content authority before making the changes.

Different phases of Waterfall model Software Development Cycle

• Requirement Gathering and analysis − All possible requirements of the system to be developed are captured in this phase and documented in a requirement specification document.

• System Design − The requirement specifications from first phase are studied in this phase and the system design is prepared. This system design helps in specifying hardware and system requirements and helps in defining the overall system architecture.

• Implementation − With inputs from the system design, the system is first developed in small programs called units, which are integrated in the next phase. Each unit is developed and tested for its functionality, which is referred to as Unit Testing.

• Integration and Testing − All the units developed in the implementation phase are integrated into a system after testing of each unit. Post integration the entire system is tested for any faults and failures.

• Deployment of system − Once the functional and non-functional testing is done; the product is deployed in the customer environment or released into the market.

• Maintenance − There are some issues which come up in the client environment. To fix those issues, patches are released. Also to enhance the product some better versions are released. Maintenance is done to deliver these changes in the customer environment.

 

Waterfall Model Advantages:

• Simple and easy to understand and use.

• It is un-discretional model. Bug sucking is not possible in each phase.

• It is used only when requirements are very clear.

• It is mainly used on Live Mission or Critical Applications.

Waterfall Model Disadvantages:

• Wrong set of requirements, it should be collected by Business Analyst. So there is a highly chances of that whole set of application is wrong.

• Testing is not done in each and every phase of Software Development Life Cycle (SDLC).

• It is time consuming.