Difference Between Agile and Waterfall

Differences Agile Software Software & Coding

In software development, there are several software development life cycle (SDLC) models available. Each of these models follows a set of phases that are unique to its type to ensure the successful software development.

This article is meant for explaining the two software development life cycle models that are Agile Model and Waterfall Model. In this article, we will also discuss the important differences between the agile model and the waterfall model.

What is Agile Model?

Agile model is the type software development life cycle model which allows the continuous interaction of the development and testing during the process of software development. The agile model involves simultaneous development and testing activities. It allows a significant interaction among customers, developers, testers, and project managers.

In the agile methodology, the entire project is sub-divided into small incremental sprints. All these sprints are completed within one to three weeks. The main purpose of agile model is to manage complex projects. Agile model primarily focus on customer feedback, collaboration, and rapid releases. However, the agile model is not a suitable SDLC model for small projects. It is because, in the case of agile model, the expenses of development of small projects are very high as compared to other models.

What is Waterfall Model?

A waterfall model is one in which the process of software development is divided into distinct phases such as requirements, design, development, testing, deployment, and maintenance. The main advantage of the waterfall model is that it is suitable for small projects where requirements are easily understandable.

In case of the waterfall model, the requirements should be clear at the beginning of the project. The testing activities in the waterfall model initiate after the completion of the development activities. Therefore, there are very high possibilities to be found later in the project development. The waterfall model is one of the simplest models to work with because in this model each phase has particular deliverables and review procedure according to its nature.

Difference between Agile Model and Waterfall Model

The following table highlights all the important differences between agile model and waterfall model −

Agile Model	Waterfall Model
It separates the project development lifecycle into multiple sprints.	The process of software development is divided into distinct phases.
It uses an incremental approach	It is a sequential design process.
It is flexible.	It is a structured process, and may be quite rigid at times.
It can be understood as a collection of multiple different projects.	The software can be developed as one single project.
Changes can be made in project development requirements after initial planning has been completed.	The requirements can't be changed once the project development starts.
It follows an iterative development approach. The process of planning, development, prototyping and software development phases can appear multiple times.	The project development phases such as designing, development, testing, are done only once in the waterfall model.
The test plan is reviewed after every sprint.	The test plan is not usually discussed during the test phase.
The requirements may change and evolve.	This method can be used for projects that have a definite set of requirements and doesn't changes.
The process of testing is performed concurrently with software development.	The 'testing' phase comes after the 'build' phase.
It uses a product mindset where software product would satisfy the requirements of end customers.	It shows a project mindset, and focuses on completing the project.
It would increase the amount of stress in fixed-price scenarios.	The risk is reduced since the price of contracts are fixed by getting the risk agreement in the beginning.
It is preferred to work with small and dedicated teams with high amounts of coordination and synchronization.	There is limited team coordination and synchronization.
It works well with time and materials, i.e. non-fixed funding.	Business analysis is done to prepare the requirement before beginning it.
Products owner with team prepares requirements just about every day during a project.	It is difficult to initiate any changes in the requirements.
Project managers are not needed since project can be managed by the entire team.	The process is generally straightforward hence project manager is required.

Conclusion

The most significant difference between the Agile model and the Waterfall model is that in the agile model, the development of software is done as a collection of many small projects, while in the waterfall model, the development of software is done as a single project.