The Spiral Model combines the idea of ​​iterative development with the systematic, controlled aspects of the Waterfall Model. The spiral model has four phases. A software project repeatedly goes through these phases in iterations called Spirals. This means that the product is released incrementally. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The identification phase begins with gathering business requirements in the basic spiral. In subsequent spirals, as the product matures, the identification of system requirements, subsystem requirements and unit requirements is done in this phase. Proof of concept includes identifying, estimating and monitoring technical feasibility and management risks, such as schedule slippage and cost overruns. After testing the build, at the end of the first iteration, the customer evaluates the software and provides feedback. This phase also includes understanding the system requirements through continuous communication between the customer and the system analyst. The design phase begins with conceptual design in the basic spiral and includes architectural design, logical module design, physical product design, and final design in subsequent spirals. In this phase, the application architecture is designed, that is, the structure of the application, such as user interface features, such as colors, text, tabs, buttons, and links. Then each module of the application is designed and finally the entire system is designed in the latest build. The customer provides feedback on this design in the evaluation phase at the end of the iteration. The construction phase refers to the production of the actual software product at each stage. In the basic spiral, the product is implemented by software developers, who code the application so that it works correctly. Developers must follow the blueprint provided by the designers. Another build is created later in development, so that new implementations can be provided, which may be more efficient. The first build is used as a backup if the second build fails. The build is tested in the evaluation phase. The evaluation phase consists of managing risks in the application used to contain and mitigate threats in the product and also testing the operation of the application, which is done to make the code more efficient and reduce errors found in building the product. The customer provides feedback on the design and construction of the system, to see how the product development is completed. The spiral model is applied when:When the budget is low and risks need to be assessedThe project presents a medium to high risk.The client is not sure of their requirements. The requirements are complex and need evaluation to be clear. Significant changes to the product are expected during the development cycle. Advantages of the spiral model: Requirements can be changed. Promotes the use of prototypes. Requirements can be defined more accurately. Users can see the system in the early stages of development. Development can be divided into modules and difficult modules can be developed earlier. Disadvantages of the model: The end of the project may not be known in advance. Management is more complex. The spiral could disappear active indefinitely. Not suitable for small or low-risk projectsWaterfallAmong the many project management models in use today, the waterfall model is one.