Both Spiral and Waterfall Model are most extensively practised type of development methodology in software industry. Both of these models are practice for better tracking and have application development in systematic way.
On the basis of type of steps or phases between both of the models we can distinguish between Spiral Model and WaterFall Model as follows −
|Sr. No.||Key||Spiral Model||WaterFall Model|
|1||Definition||Spiral Model is the development model in which the entire model is divided into various sub development phase where corresponding testing phase for each development phase is practices. In other words we can say that for every stage in the development cycle, there is an associated testing phase and corresponding testing phase of the development phase is planned in parallel.||On other hand Waterfall model there is first development of the application and after which the different testing of application take place. In other words we can say that in WaterFall the complete process is divided into several phases among which one phase should be completed in order to reach the next phase and testing is almost at end phase of the development.|
|2||Type/Nature||As mentioned above that in Spiral Model the execution of the phases i.e., development and testing happens in a sequential manner so type of Spiral Model is evolutionary in nature.||On other hand WaterFall Model is a relatively linear sequential design approach as each phase should be completed in order to reach the next phase. So type of this model is Continuous in nature.|
|3||Testing and Validation||In Spiral Model each development phase get tested at its own level and hence no pending testing occurs in this model also if any validation requires to be implemented then it could be implemented at that phase.||On other hand in case of WaterFall Model the testing occurs after development is completed and thus if any missing validation is identified to be implemented then first that phase of development needs to be recognized and then that validation get implemented.|
|4||Cost and Complexity||As sequential phases need to be functional hence the cost is higher as compared to that of WaterFall Model also the complexity is more than WaterFall.||On other hand in WaterFall Model due to linear development only one phase of development is operational and hence cost and complexity is low as compared to that of Spiral Model.|
|5||Defects||In Spiral Model the probability of total number of defects in the development of application is low as testing is done in parallel to the development.||On other hand in WaterFall Model the probability of total number of defects in the development of application is high as testing is done post development.|