Software Process Model: Spiral Model
Spiral Model was originally proposed by "Boehm". Rather than represent the software process as a sequence of activities with some backtracking from one activity to the another, the process is represented as a SPIRAL.
Each loop in spiral model represents a phase of the Software Process.
In this model, developers define and implement features in order of Decreasing Priority.
Exact numbers of loops in the spiral is "Not fixed".
This model considers RISK, which often goes "UN-Noticed" by most other models.
Each loop of the spiral represent a phase of the software process. And it has four phases.
The Four Phases of Spiral Model
1) Determining Object or Objective Setting or Planning Object
A detailed management plan is drawn up and "Project Risk" are identified.
2) Identify And Resolve Risks or Risk Assessment And Reduction or Risk Analysis:
This phase has been added specially in order to identify and resolve all possible risks in project development. If RISKS indicate any kind of UNCERTAINLY in requirement, Prototyping may be used to proceed with the available data and find out solution in order to deal with the Potential changes in the Requirements.
3) Development and Test or Engineering or Development And Validation:After resolving the identified risk, the actual development of the project is carried out in this..
4) Plan Next Iteration or Planning or Reviewing And Planning:
The prototype is reviewed and decision made whether to continue with a further loop of the spiral. It is decided to continue, plans are drawn up for the next phase of the project.
Risk means something that can go WRONG.