Waterfall Methodology vs Agile
There are number of different software development methodologies used in the software industry today. Waterfall development method is one of the earliest software development methods. Waterfall software development methodology is a sequential model in which, each phase is completed in full and followed in a fixed order. Agile model is a more recent software development model introduced to address the shortcomings found in existing models. Main focus of Agile is incorporating testing as early as possible and releasing a working version of the product very early, by breaking down the system in to very small and manageable sub parts.
What is Waterfall Methodology?
Waterfall methodology is one of the earliest software development models. As the name suggests, it is a sequential process in which progress flows through several phases top to bottom, analogous to a waterfall. The phases of Waterfall model are requirement analysis, design, development, testing and implementation. Here, each phase is fully completed before moving on to the next phase. This model was a direct result of simply adapting hardware-oriented development method (found in manufacturing and construction industries), at a time there was no formal model for software development.
What is Agile?
Agile is a very recent software development methodology based on the agile manifesto. This was developed to solve some shortcoming in traditional software development methodologies. Agile methods are based on giving high priority to the customer participation early in the development cycle. It recommends incorporating testing by the customer early and often as possible. Testing is done at each point when a stable version becomes available. The foundation of Agile is based on starting testing from the beginning of the project and continuing throughout to the end of the project.
Key value of Agile is “quality is the team’s responsibility”, which stresses that the quality of the software is the responsibility of the whole team (not just the testing team). One other important aspect of Agile is breaking down the software in to smaller manageable parts and delivering them to customer very quickly. Delivering a working product is at utmost importance. Then the team continues to improve the software and deliver continuously at each major step. This is achieved by having very short release cycles called sprints and getting feedback for improvement at the end of each cycle. Contributors without much interactions of the team such as developers and testers in the earlier methods, now work together within the Agile model.
What is the difference between Waterfall Methodology and Agile?
Agile model delivers a working version of the product very early compared to Waterfall methodology. As more features are delivered incrementally, customer can realize some of the benefits early on. Testing cycle time of Agile is relatively short compared to Waterfall methodology, because testing is done parallel to development. Waterfall model is very rigid and relatively less flexible than the Agile model. Because of all these advantages, Agile is preferred over the Waterfall methodology at the moment.