There are various software development life cycle models specified and designed which are followed during the software development process. These models are also referred as Software Development Process Models". Each process model follows a sequence of steps unique to its type to ensure success in the process of software development.
Here, are some important phases of SDLC life cycle:
Waterfall Model: The waterfall is a universally accepted SDLC model. In this method, the whole process of software development is divided into various phases. In this SDLC model, the result of one aspect acts as the input for the next step.
This SDLC model is documentation-intensive, with previous phases documenting what need be performed in the subsequent phases.
RAD Model: RAD or Rapid Application Development process is an adoption of the waterfall model; it targets developing software in a short period. SDLC RAD model has the following phases
Spiral Model: The spiral model is a risk-driven process model. This SDLC model helps the group to adopt elements of one or more process models like a waterfall, incremental, waterfall, etc.
V-Model: 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.
Incremental Model: The incremental model is not a separate model. It is necessarily a series of waterfall cycles. The requirements are divided into groups at the start of the project. For each group, the SDLC model is followed to develop software. 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.
Agile Model: 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. All of these builds are provided in iterations, and each iteration lasts from one to three weeks.
Iterative Model: 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.
Big bang model: 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 which are working together. It is also useful for academic software development projects. It is an ideal model where requirements are either unknown or final release date is not given.
Spiral Model: The spiral model is a risk-driven process model. This SDLC model helps the team to adopt elements of one or more process models like a waterfall, incremental, waterfall, etc.
This model adopts the best features of the prototyping model and the waterfall model. The spiral methodology is a combination of rapid prototyping and concurrency in design and development activities.