What is a Waterfall methodology?

Waterfall Model methodology which is also called a Linear Sequential Life Cycle Model. Waterfall Model followed in the sequential order, and so project development team only moves to the first stage of development or testing if the previous steps completed successfully.

What is an Agile methodology?

Agile methodology is a process that helps continuous iteration of development and testing in the software development process. In this model, development and testing activities are simultaneous, unlike the Waterfall model.  Agile methodology allows more communication between customers, developers, managers, and testers.

Advantages of the Waterfall Model:

  • Waterfall Model is one of the easiest models to manage. Because of its nature, each stage has an exact deliverables and a review process.
  • Waterfall Model is only implemented on smaller size projects because requirements are easy to understand.
  • Quicker delivery of the project.
  • Procedure and results are well documented.
  • Simply flexible method for shifting teams.
  • This project managing methodology is helpful to manage dependencies.

Advantages of the Agile Model:

  • It is focused on the client process. So, it makes sure that the client is continuously involved during every stage.
  • Agile teams are extremely motivated and self-organized so it likely to provide a better result from the development projects.
  • Agile software development method assures that the quality of the development is maintained.
  • The process is completely based on incremental progress. Therefore, the client and team know exactly what is complete and what is not. This reduces risk in the development process.

Limitations of the Waterfall Model:

  • It is not an ideal model for a large size project.
  • If the requirement is not clear at the beginning, it is a less effective method.
  • Very difficult to move back to makes changes in the previous phases.
  • The testing process starts once development is over. Hence, it has high chances of bugs to be found later in development where they are expensive to fix.

Limitations of the Agile Model

  • It is not a useful method for small development projects.
  • It requires an expert to take important decisions in the meeting.
  • Cost of implementing an agile method is a little more compared to other development methodologies.
  • The project can easily go off track if the project manager is not clear what outcome he/she wants.

 

AGILE WATERFALL
It separates the project development lifecycle into sprints. The software development process is divided into distinct phases.
It follows an incremental approach. Waterfall methodology is a sequential design process.
Agile methodology is known for its flexibility. The waterfall is a structured software development methodology so most times it can be quite rigid.
Agile can be measured as a collection of many different projects. Software development will be completed as one single project.
Agile is quite a flexible method which allows changes to be made in the project development requirements even if the initial planning has been completed. There is no scope of changing the requirements once the project development starts.
Agile methodology, follow an iterative development approach because of this planning, development, prototyping and other software development phases may appear more than once. All the project development phases like designing, development, testing, etc. are completed once in the Waterfall model.
A test plan is reviewed after each sprint. The test plan is rarely discussed during the test phase.
Agile development is a process in which the expected requirements needs to change and evolve. The method is ideal for projects which have definite requirements and changes not at all expected.
In Agile methodology, testing is performed parallel with software development. In this methodology, the “Testing” phase comes after the “Build” phase.
Agile introduces a product mindset where the software product satisfies requirements of its end customers and changes itself as per the customer’s demands. This model shows a project mindset and places its focus completely on accomplishing the project.
The agile methodology works extremely well with Time & Materials or non-fixed funding. It may increase stress in fixed-price scenarios. Reduces risk in the firm fixed price contracts by getting risk agreement at the beginning of the process.
High degree of coordination and synchronization Team coordination/synchronization is very limited.
Team and Product owner prepares requirements every day during a project. Business analysis prepares requirements before the beginning of the project.
Test team can also take part in the requirements change without problems. It is difficult for the test to initiate any change in requirements.
Description of project details can be changed anytime during the SDLC process. Detail description needs to implement the waterfall software development approach.

The Agile Team members are interchangeable as a result, they work faster. There is also no need for project managers because the projects are managed by the entire team.

In the waterfall method, the process is always straightforward so, project manager plays an essential role during every stage of SDLC.

Conclusion:

Agile and Waterfall are very different software development methodologies and are good in their respective way.

However, there are certainly major differences highlighted below –

  • Waterfall model is perfect for projects which have distinct requirements, and no changes are estimated. On the other hand, Agile is best appropriate where there is a higher chance of frequent requirement changes.

  • The waterfall is easy to manage, sequential, and rigid method.

  • Agile is very flexible and it possible to make changes in any stage.

  • In an Agile process, requirements can change frequently. However, in a waterfall model, it is defined only once by the business analyst.

  • In Agile Description of project, details can be altered anytime during the SDLC process which is not possible in the Waterfall method.