Software Development Models

Both the models, the Waterfall model, and Spiral model are used in software development. The waterfall model is also known as the classical or linear model because it follows sequential stages while the spiral model does not follow the sequential stages it follows the evolutionary way. The amount of risk in the waterfall model is more as compared to the spiral model because the errors or risks are identified and refined after the completion of each stage.

Waterfall Model

The waterfall model is a classical software life cycle model. The model’s flow is sequential as the suggests similar to a waterfall in a top-down fashion, that is the reason it is also known as the linear sequential model. It has various phases such as requirement analysis, design, coding, testing, integration, implementation, and maintenance.

The waterfall model works in a sequential method. In the waterfall model errors or risks are identified and rectified after the completion of stages. The waterfall model is adopted by customers. The waterfall model is applicable for a small project. In the waterfall model requirements and early-stage planning is necessary. Flexibility to change in the waterfall model is Difficult. There is a high amount of risk in the waterfall model. The waterfall model is comparatively inexpensive.

Spiral Model

The spiral model is an evolutionary type of software life cycle model which merges the features of the prototype model and waterfall model. It has the potential for developing the incremental versions of the software by implementing the interactiveness of the prototype model and controlled methodical of the linear segmental model. The outcome of the spiral model is the series of incremental releases of the software.

While the spiral model works in the evolutionary method. Inspiral model errors or risks are identified and rectified earlier. While spiral model is adopted by developers. While the Spiral model is used for a large project. While in spiral model requirements and early stage planning is necessary if required. Flexibility to change in the spiral model is not difficult. There is a low amount risk in spiral model. While cost of spiral model is very expensive.

The Waterfall and Spiral models are the process models used for developing software in a well-defined, systematic and cost-effective way. The major difference between these software process models waterfall and the spiral is that the waterfall model is comprised of the separate and isolate phases of specification and development. On the other hand, in a spiral model the different specification, development and validation phases are interleaved.

The spiral model is different from waterfall model due to the feature of definite identification of the risk which reduces the chances of failure of the project. On the other hand, the waterfall is quite risky as there are no iterations everything have to be done at once meaning the requirements are gathered, planned, designed, coded, integrated at one time for a software product.