Difference between V-model and Incremental model

1. V model:
V-model is the most important model that is used in the process of software testing. It is also known as Verification and Validation Model. It is Introduced by the late Paul Rook in the 1980s. V-model is a sequential process in which the next phase begins only after the completion of the present phase. In this model, steps don’t move in a linear way while the steps are bent upwards. 

2. Incremental Model:
Incremental Model is a model of software development where the product is, analyzed, designed, implemented, and tested incrementally until the product is finished. Multiple development cycles take place and these cycles are divided into smaller modules. Generally, working software in an incremental model is produced during the first module Each subsequent release of the module adds function to the previous release. In the incremental model, the process continues till the complete system is achieved. 

Difference between V-model and Incremental model :

S. No.	V MODEL	INCREMENTAL MODEL
1.	V model is software development model but development and testing are not concurrent.	Incremental Model is a software development model where the product is, analyzed, designed, implemented and tested incrementally until the product is finished.
2.	In V-model testing activities start with the first stage.	Testing is done in incremental model after every iteration of phase.
3.	Flexibility of V-model is Little flexible.	Flexibility to change in incremental model is Easy.
4.	Cost of V-model is expensive.	Cost of incremental model is also Low.
5.	Guarantee of success through V-model is high.	Guarantee of success through incremental model is low.
6.	In this user involvement is also only in beginning.	In this user Involvement is only at the beginning.
7.	It is not iterative.	It is iterative.
8.	Advantages- Simple to use Time saving because testing activities such as planning and designing tests take place prior to coding. Defects detect at early stage Prevents the flow of defects downward. Suitable for small projects	Advantages- Availability of working software quickly and early in the development cycle Customer can comment on each built. Initial delivery cost is less. Flexible Involves less cost for changing requirements Risk management during each iteration
9.	Disadvantages- Rigid Non-availability of early prototypes of the software as it is developed during implementation phase. Test documents and other necessary documents requires to be updated in between in case of any changes.	Disadvantages- Requires careful planning and design. Detailed definition of the entire system is required before it can be disassembled and built gradually.
10.	When to use- For small to medium-sized projects Only when there is availability of  technical resources and required expertise.	When to use- When requirements are clear and understandable of the complete system. Involving a new technology Need the product quickly Appropriate skill set resources are unavailable