Final answer:
The Spiral Model is a software development life cycle model incorporating linear development in an iterative, four-phase process, with emphasis on planning, risk analysis, engineering, and evaluation. It provides flexibility and a framework for continuous improvement, which is especially valuable for complex and evolving projects.
Step-by-step explanation:
The software development life cycle model that uses linear development concepts in an iterative, four-phase process is commonly known as the Spiral Model. This model combines elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. There are four major phases in the Spiral Model, which include:
- Preparatory Phase
- Implementation and Learning Phase
- Program Evaluation Phase
- Development of Lessons Learned
The Spiral Model is particularly useful when requirements are not well-understood or expected to change over time. By undergoing multiple iterations, or 'spirals', the development team can refine the product through successive refinements based on what is learned from earlier phases. This also allows weaknesses and potential improvements to be identified and addressed early on, making it ideal for projects where user requirements may be complex or evolving.
The iterative nature of the spiral design process can lead to a better end product but may require more time and resources compared to linear approaches. Nonetheless, because the teams go through cycles of planning, risk analysis, engineering, and evaluation, this model is considered highly flexible and capable of handling unanticipated risks.