List down all models of SDLC?
Published: 2023-09-25 04:02:45

There are different software development life cycle models specify and design, which are followed during the software development phase. These models are also called "**Software Development Process Models**." Each process model follows a series of phase unique to its type to ensure success in the step of software development.
Below are some of the important SDLC models followed by different organizations as per their needs.
**<u>Waterfall Model:</u>**
In this model, the whole process of software development is divided into various phases. The waterfall model is a continuous software development model in which development is seen as flowing steadily in a linear flow through the steps of requirements analysis, design, implementation, testing (validation), integration, and maintenance.
**<u>RAD Model:</u>**
RAD or Rapid Application Development process is an adoption of the waterfall model; it targets developing software in a short period. The RAD model is based on the concept that a better system can be developed in lesser time by using focus groups to gather system requirements.
**<u>Spiral Model:</u>**
The spiral model is a risk-driven process model. The spiral technique is a combination of rapid prototyping and concurrency in design and development activities. Each cycle in the spiral begins with the identification of objectives for that cycle, the different alternatives for achieving the goals, and the constraints that exist. This is the first quadrant of the cycle (upper-left). The next step in the cycle is to evaluate these alternatives based on the objectives and constraints. The focus of evaluation is based on the risk perception. Next step is to develop strategies that solve uncertainties and risks. This step may involve activities such as benchmarking, simulation, and prototyping.
**<u>V-Model:</u>**
In this type of SDLC model testing and the development, the step is planned in parallel. So, there are verification phases on the side and the validation phase on the other side. V-Model joins by Coding phase.
**<u>Incremental Model:</u>**
This is necessarily a series of waterfall cycles. The SDLC process is repeated, with each release adding more functionality until all requirements are met. In this method, each cycle act as the maintenance phase for the previous software release. Modification to the incremental model allows development cycles to overlap. After that subsequent cycle may begin before the previous cycle is complete.
**<u>Agile Model:</u>**
Agile methodology is a practice which promotes continues interaction of development and testing during the SDLC process of any project. In the Agile method, the entire project is divided into small incremental builds. Builds are provided in iterations, and each iteration lasts from one to three weeks. This is one of the widely used models in the industry.
**<u>Iterative Model:</u>**
It is a particular implementation of a software development life cycle that focuses on an initial, simplified implementation, which then progressively gains more complexity and a broader feature set until the final system is complete. In short, iterative development is a way of breaking down the software development of a large application into smaller pieces.
**<u>Big bang model:</u>**
Big bang model is focusing on all types of resources in software development and coding, with no or very little planning. The requirements are understood and implemented when they come. This model works best for small projects with smaller size development team where requirements are either unknown or final release date is not given.
**<u>Prototype Model:</u>**
The prototyping model starts with the requirements gathering. The developer and the user meet and define the purpose of the software, identify the needs, etc. A 'quick design' is then created. This design focuses on those aspects of the software that will be visible to the user. It then leads to the development of a prototype. The customer then checks the prototype, and any modifications or changes that are needed are made to the prototype.