Software Testing | Tutorial (SDLC Models)

 

 SDLC Life Cycle Models

There are various SDLC life cycle models used to run the development project. They all consist of the same basic steps we’ve mentioned above ,which are equally important. The main difference between the models is that they all plan the necessary development activities and steps in different ways.

         image : sdlc model

1. Waterfall model

SDLC Waterfall model is a linear and sequential software development model in which project phases follow one another. The process goes forward like water in a cascading waterfall, hence the name Waterfall. The model presupposes that the team moves one step at a time making sure their work is complete before going to the next phase. It means that first, the team should gather all the requirements for the whole project. After the requirements are fully defined, the team is ready to go to the design stage, where all the documents describing how to implement these requirements are created. The Waterfall model requires very strong documentation – goals, specifications, and tasks have to be as precise as possible.

After that, the developers are ready to do their job – transform requirements into the working product. When the coding stage is over, the product is tested to reveal possible errors and inconsistencies. This gives a team the possibility to finetune the software, eliminate all shortcomings and prepare the product for deployment. The working software product is then demonstrated to the customer.

     image: waterfall model

Waterfall Methodology can be used when:

Requirements are not changing frequently

Application is not complicated and big

Project is short

Requirement is clear

Environment is stable

Technology and tools used are not dynamic and is stable

Resources are available and trained

Advantages -

- Before the next phase of development, each phase must be completed.

- Suited for smaller projects where requirements are well defined.

- Project is completely dependent on project team with minimum client intervention.

- Any changes in software is made during the process of the development.

Dis-Advantages -

- Error can be fixed only during the phase.

- It is not desirable for complex project where requirement changes frequently.

- Small changes or errors that arise in the completed software may cause a lot of problems.