What is Spiral Model?
Spiral Model is a combination of a waterfall model and iterative model. Each phase in spiral model begins with a design goal and ends with the client reviewing the progress. The spiral model was first mentioned by Barry Boehm in his 1986 paper.
The development team in Spiral-SDLC model starts with a small set of requirement and goes through each development phase for those set of requirements. The development team adds functionality for the additional requirement in every-increasing spirals until the application is ready for the production phase.
Spiral Model of SDLC spans into four phases:
|Spiral Model Phases||Activities performed during phase|
When to use Spiral-SDLC Model?
- When project is large
- When releases are required to be frequent
- When creation of a prototype is applicable
- When risk and costs evaluation is important
- For medium to high-risk projects
- When requirements are unclear and complex
- When changes may require at any time
- When long term project commitment is not feasible due to changes in economic priorities
Advantages and Disadvantages of Spiral Model