What is the Spiral Model?

The Spiral Model

The Spiral Model is a Software Development Life Cycle model. A Software Development Life Cycle is a sequence of processes and practices that, when followed, eventually produce software.

The spiral model has a number of phases – each phase can be divided into four quadrants. A graphical representation of this is shown above, where each loop of the spiral represents one phase.

Processes

The phases in the spiral model work much like the Iterative Model. In the first phase, the complete software is built and in the subsequent phases, changes and improvements are made. Each phase is divided into the following processes:

1. The Objectives Identification stage involves the identification of the objectives of the phase. All potential solutions are also determined during this stage.
2. The Risk Management stage involves the evaluation of all potential solutions to find the best solution. The risks associated with this solution are then identified and resolved.
3. In the Development stage, the actual programming and development of the software is done. Thorough testing is done to ensure quality.
4. Finally, there’s Review and Planning, which evaluates the current version of the software by the client and the​ subsequent planning for the next phase.