Spiral model is used for high risky projects. here we make a part verify that then do enhancements and again verify and so on upto completion of project.
Spiral model is developed in recognition of the fact that systems development projects tend to repeat the stages of analysis design and code as part of the prototyping process. Spiral model includes best features of both the classic Waterfall SDLC and the Prototyping approach.
Spiral model is to find more number of defects in the Software. this type of model is suitable to develop complex application. The development process is repeated in each deteration till the final product is released.
