Difference Between Waterfall Vs V Model: There are many software development methodologies and every company has its own way of developing software. The methodology adopted by the company will be based on their development needs and the skills of the developers. Today we will be discussing two major software development methodologies Waterfall Vs V Model.
Both Waterfall Vs V models are similar, however, their approach to software development is completely different.
Waterfall Model of Software Development Life Cycle
The Waterfall Model is a sequential model where the process starts from the beginning and ends at the end. For example, if we want to develop a house, the first task is to create a blueprint for it. The second step will be getting the bricks and cement ready which will again involve certain other tasks to be completed. The third step is laying it down and so on until the house is built completely.
In Software development, Waterfall Model is followed in the same way. It starts with a requirements document which contains all the details about what is to be developed, how it is to be developed, and finally how it is to function. Once the requirements are complete, development can begin, by creating a blueprint for the software (architecture) and then getting the programmers to develop it accordingly. Once the development is completed, it has to be tested, and finally, once testing is complete, the software is delivered to the customer.
The Waterfall Model does not have any safety nets in it, so if any problems are encountered during the development phase, it has to be taken back to the previous stage and restarted. This is one of the major disadvantages of using the Waterfall Model as it requires a lot of rework if something is done wrong.
V Model of Software Development Life Cycle
Unlike Waterfall Models where the development process is sequential, the V Model is a cyclical model which allows feedback from previous stages, to improve the next stage.
In V Model, the first stage is to identify the problem or define a ‘requirement’. The requirements are gathered from various sources like User Interviews, Market surveys, etc. Then after the requirements are gathered, it is transformed into an analysis model using various methods like Brainstorming, Data Flow Diagrams, etc. This is called the first cycle of the V Model.
If the first cycle is successful, then it can be taken into the development stage and this is the second cycle of the V Model. Once the development is completed, it can be tested and this will be termed as the third cycle of the V Model. Once the testing is done, it will be delivered to the customer and this will be termed as the fourth cycle of the V Model. If there are any problems with the delivery, then it can be tracked down and corrected in the next cycle. This is how V Model works.
The main advantage of the V Model is that it can deliver the software in a short period of time. During every cycle, changes can be made to the software if everything is not working according to the plan.
Now let us discuss various aspects of both the Waterfall Model and V Model:
Difference Between Waterfall Vs V Model
There are various differences between Waterfall Vs V Model. Let us discuss them one by one.
1) Process Characteristics:
Waterfall Model:
The Waterfall Model is sequential in nature and every stage is completed before the next one begins. There are no chances to go back to the previous stage, once a task is completed.
V Model:
Unlike Waterfall Models where every stage has to be finished before moving on to the next one, V Model allows the programmer to check and change things if something is wrong or needs improvement. After every cycle (stage), the programmer can make changes to the software as needed. This is one of the most important differences between Waterfall Models and the V Model.
2) Deliverables:
Waterfall Model:
In Waterfall Model, the software undergoes various stages to be developed completely. There are no deliverables as such, as every stage is completed before the next one begins.
V Model:
In V Model, there are deliverables at every stage (cycle) of development. There are no deliverables at the end of each phase, as things can be changed depending on requirements.
3) Requirements Specification:
Waterfall Model:
Requirements are gathered from various sources and then they are analyzed using various methods. Once the requirements are collected, they are analyzed, and then they can be taken into development.
V Model:
As in V Model, requirements are gathered from various sources (Interview, Survey, etc.) and they are analyzed using various methods (Brainstorming, Data Flow Diagrams, etc.). Once the requirements are ready, we can move on to develop the software. This is one of the major differences between the Waterfall Model and the V Model.
4) Natural Flow of Work:
Waterfall Model:
In Waterfall Model, it is impossible to go back to the previous stage. Once a task is done, the next one is started.
V Model:
Unlike Waterfall Models where it is impossible to go back and check on previous stages, V Model allows the programmer to go back and check on all the previous stages. This is one of the major differences between the Waterfall Model and the V Model.
5) Nature of Model:
Waterfall Model:
The Waterfall Model is a linear model. It means it has one entry and exit point.
V Model:
Unlike Waterfall Models where the entry and exit points are fixed, V Model is cyclical in nature. There are four entry and exit points.
6) Continuous Integration Vs Big Bang Integration:
Waterfall Model:
In Waterfall Models, one phase has to be completed before the next one begins. All phases are independent of each other in this way.
V Model:
As discussed earlier, V Model is a cyclical model where all the phases are connected to each other. There is an entry and exit point between the two phases. This makes V Model much flexible and better than Waterfall Model.
7) Updating Source Code:
Waterfall Model:
In Waterfall models, the source code is updated at the end of each phase.
V Model:
As in V Model, the source code can be updated after every cycle. This makes V Model more flexible and better than Waterfall Models.
8) Iterative Vs Linear Development:
Waterfall Model:
Waterfall Model is a linear model. It means once a phase or stage is completed, one has to go through the process from the beginning. There are no chances to go back and re-do a phase or stage if it is not completed properly.
V Model:
As in V Models, one has to go through the process only once. After every cycle or phase, one can go back and re-do the stage if needed. This is one of the major benefits of the V Model over Waterfall Models.
9) Multiple Entry and Exit Points:
Waterfall Model:
All stages or phases in Waterfall Model are independent of each other. All stages have only one entry and exit point which makes it more restrictive than V Models where there are four entry and exit points.
V Model:
Unlike the Waterfall Model where all stages are independent of each other with only one entry and exit point, the V Model is cyclical in nature. Each stage or phase has four entry and exit points. This not only makes V Models much flexible than Waterfall Model but also makes it a more flexible model than any other software development model.
10) Business Plan Vs Software Specification:
Waterfall Model:
The Waterfall Model does not follow a set definition or procedure to develop the software.
V Model:
Unlike Waterfall Models where it is not possible to define a set process or procedure, in V Models there are various definitions and procedures to be followed.
11) Stakeholders:
Waterfall Model:
In Waterfall Models, the stakeholders can only provide input and requirements (if any) at the beginning of Phase 1 and again at the end of Phase 4.
V Model:
Unlike Waterfall Models, in V Models the stakeholders can provide input at any time during all phases and also try to see how their requirements are progressing. This is again one of the major advantages of the V Model over Waterfall Models.
12) Testing:
Waterfall Model:
In Waterfall Models, there is no chance of testing a software module or program during its development. This makes it difficult to find the bugs in software before releasing it.
V Model:
Unlike Waterfall Models, in V Model there are various chances of testing the software during its development. This makes it easier to find and remove the bugs from the software before releasing it.
13) Incremental Vs Piecemeal:
Waterfall Model:
In Waterfall Models, variations to project objectives, requirements, or plans cannot be made easily.
V Model:
Unlike Waterfall Models where the variations in project objectives and requirements cannot be done easily, in the V Model variations can be made at any time. This makes V Models much flexible than Waterfall Models and other software development models.
14) Risk Management:
Waterfall Model:
In Waterfall Models, the risk management process is designed for each and every individual phase.
V Model:
Unlike Waterfall Models, in V Models the risk management process is designed for each and every stage or phase. This makes it better than Waterfall Models.
15) Fixed Vs Flexible:
Waterfall Model:
In Waterfall Models, the full package of work is done before starting a new phase.
V Model:
Unlike Waterfall Models, in V Models work can be done on the previous phase or stage when starting a new phase or stage. This makes it more flexible than Waterfall Model.
16) Bug Fixing:
Waterfall Model:
In Waterfall Models, the bug fixing is done at the end of Phase 4.
V Model:
Unlike Waterfall Models, in V Models the bug fixing is done at any time during all phases and stages. This makes it more flexible than Waterfall Model.
17) Debugging:
Waterfall Model:
In Waterfall Models, the debugging is done at the end of Phase 4.
V Model:
Unlike Waterfall Models, in V Models the debugging is done at any time during all phases and stages. This makes it more flexible than Waterfall Model.
18) Dependencies:
Waterfall Model:
In Waterfall Models, the dependencies are established at the beginning of Phase 1 and not touched again until the end of Phase 4.
V Model:
Unlike Waterfall Models where the dependencies are established at the beginning of Phase 1 and not touched again until the end of Phase 4, in the V Model the dependencies are re-evaluated at every phase or stage.
19) Risk Analysis:
Waterfall Model:
There is no place for Risk Analysis in Waterfall Models.
V Model:
In V Model there is a place for Risk Analysis.
20) Requirements Gathering:
Waterfall Model:
In Waterfall Models, the requirements are established at the beginning of the phase or stage and then again at the end of it.
V Model:
Unlike Waterfall Models where the requirements are established at the beginning of the phase or stage and then again at the end of it, in V Models the requirements are re-evaluated at every phase or stage.
21) Modular Vs Non-Modular:
Waterfall Model:
In Waterfall Models the work is done in phases and then integration happens at the end.
V Model:
In V Modules the work is done in stages or phases but there is no integration done at the end.
22) Documentation:
Waterfall Model:
In Waterfall Models, there is no place for documentation of work done in each phase or stage.
V Model:
In V Models, there is a place for documentation of work done in each phase or stage.
23) Multiple Teams:
Waterfall Model:
In Waterfall Models, one Team works on one phase.
V Model:
Unlike Waterfall Models where one team works on one phase, in V Model multiple teams work on multiple phases.
Conclusion:
V Model has lots of advantages over the Waterfall model. When I compare the two models, I would prefer the V model because it is more practical and can be extended for any software development lifecycle.
Waterfall Model has its advantages too, depending on the situation. Other software development models are also good but they do not provide flexibility as V Model does.
Thanks for reading! 🙂
There is still lots to learn about V Model and we will always be learning. Please come back soon and check out more articles coming soon.
