Software Development Models

Testing activities are related to software development activities. Different development life cycle models need different Approaches to Testing.

Different software development models are:-

·             Waterfall Model
·        V- Model
·        Incremental Model
·        Rapid Application Development Model
·        Agile Model
·        Iterative Model 

            Spiral Model

Waterfall Model

Waterfall Model was the first process model to be introduced. Waterfall Model consists of several phases and each phase must be completed fully before the next phase can begin. Phases never overlap in a Waterfall Model. At the end of each phase a review is done to determine if the project is on the right path and whether or not to continue or discard the project.

V Model

V Model means verification and validation model.  The ‘V’ – shaped life-cycle is a sequential path of execution of processes. Each phase must be completed before the next phase begins. Testing of the product is planned in parallel with a corresponding phase of development. The common type of V-Model uses four test levels corresponding to the four development levels. The four levels are:-

·        Unit Testing

·        Integration Testing

·        System Testing

·        User Acceptance Testing

Incremental Model

In Incremental Model the whole requirement is divided in to various builds. Multiple development cycles take place here, making the life cycle a multi-waterfall cycle. A working version of software is produced during the first module. So you can have working software early on during the software life cycle.

Rapid Application Development Model

RAD model is a type of environmental model. In RAD model, the components or function are developed in parallel as if they were mini projects.

Agile Development Model

It’s also a type of Incremental model. Software is developed in incremental and rapid cycles. This results in small incremental releases with each release building on previous functionality. Software quality is maintained by thoroughly testing each release.

Iterative Model

Iterative life cycle model does not attempt to start with a full specification of requirements. Instead it begins by specifying and implementing just part of the software which can then be reviewed in-order to identify further requirements. The process is then repeated producing a new version of the software for each cycle of the model.

Spiral Model

It is similar to the incremental model with more emphasis placed on risk analysis.