Agile vs. Waterfall Methodology

There are several ways to manage projects, especially when you’re developing software. Two of the most prominent methods are Waterfall and Agile.

 

Waterfall: which might be more properly called the “traditional” approach. The Waterfall model is a sequential design process, used in software development processes, in which progress is seen as flowing steadily downwards (like a Waterfall) through the phases of conception, initiation, analysis, design, construction, testing, implementation and maintenance. It is one of the most widely used Software Development Process. It is also called as “Linear Sequential model” or the “classic life cycle” or iterative model. It is widely used in the commercial development projects.

 

Agile: a specific type of Rapid Application Development, newer than Waterfall. Agile software development can be described as a set of principles for software development under which requirements and solutions evolve through the collaborative effort of self-organizing cross-functional teams. It advocates adaptive planning, evolutionary development, early delivery, and continuous improvement, and it encourages rapid and flexible response to change. These principles support the definition and continuing evolution of many software development methods.

Agile development mainly targets complex systems and product development with dynamic, non-deterministic and non-linear characteristics. Accurate estimates, stable plans, and predictions are often hard to get in early stages, and confidence in them is likely to be low.

 

Difference between Agile and Waterfall Methodologies

One of the differences between Agile and Waterfall is the approach to quality and testing. In the Waterfall model, there is always a separate testing phase after a build phase; however, in Agile development testing is completed in the same iteration as programming.

Because testing is done in every iteration users can frequently use those new pieces of software and validate the value. After the users know the real value of the updated piece of software, development teams can make better decisions about the software’s future. Having a value retrospective and software re-planning session in each iteration helps the team continuously adapt its plans so as to maximize the value it delivers.

This iterative approach supports a product rather than a project mindset. This provides greater flexibility throughout the development process; whereas on projects the requirements are defined and locked down from the very beginning, making it difficult to change them later. Iterative product development allows the software to evolve in response to changes in business environment or market requirements. Because of the short iteration style of Agile software development, it also has strong connections with the lean startup concept.

 

Some of the major advantages of the Waterfall Model are as follows −

 

  • Simple and easy to understand and use

  • Easy to manage due to the rigidity of the model. Each phase has specific deliverables and a review process.

  • Phases are processed and completed one at a time.

  • Works well for smaller projects where requirements are very well understood.

  • Clearly defined stages.

  • Well understood milestones.

  • Process and results are well documented.

 

Waterfall Model – Disadvantages

 

The disadvantage of Waterfall development is that it does not allow much reflection or revision. Once an application is in the testing stage, it is very difficult to go back and change something that was not well-documented or thought upon in the concept stage.

 

Advantages of the Agile approach are:

  • The customer has frequent and early opportunities to see the work being delivered, and to make decisions and changes throughout the development project.
  • The customer gains a strong sense of ownership by working extensively and directly with the project team throughout the project.
  • Agile can more quickly produce a basic version of working software which can be built upon in successive iterations if time to market for a specific application is a greater concern than releasing a full feature set at initial launch.
  • Development is often more user-focused with delivering more value for the customer.

Both the Waterfall and Agile methodologies have their strengths and weaknesses. The key to deciding which methodology is right for you, comes down to the context of the project. Will there be a rapid change with the project? If so, Agile methodology is the perfect fit. Do you know exactly what you need? Maybe Waterfall is the better option. Consider taking aspects of both methodologies and combining them in order to make the best possible output from the project you’re managing.

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