Difference between Waterfall Model and Spiral Model

Both the models, Waterfall model and Spiral model are used in software development. Waterfall model is also known as classical or linear model because it follows sequential stages while the spiral model does not follow the sequential stages it follows the evolutionary way. The amount of risk in waterfall model is more as compared to spiral model because the errors or risks are identified and refined after the completion of each stages. There are some difference between these two models waterfall and spiral model which are given below:

S. No.	Waterfall Model	Spiral Model
1.	The Waterfall model is simple and easy.	The spiral model is a lot more complex.
2.	The waterfall model works in a sequential method.	While the spiral model works in the evolutionary method.
3.	In the waterfall model errors or risks are identified and rectified after the completion of stages.	In the spiral model errors or risks are identified and rectified earlier.
4.	The waterfall model is adopted by customers.	While the spiral model is adopted by developers.
5.	The waterfall model is applicable for small projects.	While the Spiral model is used for large projects.
6.	In waterfall model requirements and early stage planning is necessary.	While in spiral model requirements and early stage planning is necessary if required.
7.	Flexibility to change in waterfall model is Difficult.	Flexibility to change in spiral model is not Difficult.
8.	There is high amount risk in waterfall model.	There is low amount risk in spiral model.
9.	Waterfall model is comparatively inexpensive.	While cost of spiral model is very expensive.
10.	Customer involvement is minimum in Waterfall Model	In the Spiral Model Customer involvement is high.
11.	It requires least maintenance.	It requires typical maintenance.
12.	It is based on linear framework type.	It is based on linear and iterative framework type.
13.	Testing is done after the coding phase in the development life cycle.	Testing is done after the engineering phase in the development cycle.
14.	Reusability is extremely unlikely.	To a certain extent, reusability is possible.
15.	Customer control over the administrator is very limited.	Customers have control over the administrator as compared to waterfall model.