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  • Volodymyr Kis

5 reasons why Agile is better than Waterfall

If you're wondering what's the real difference between Agile and Waterfall and why the one is better than the other, you've come to the right place. In this comparison, you'll find top 5 reasons why you should consider Agile over Waterfall software delivery approach.




What is Agile?


Agile is an iterative, time boxed approach to software delivery where teams first build something, learn from it and then adapt what they're building and how they're building it.

The most common agile framework that most agile software teams use is Scrum. Scrum uses sprints, which are time boxed iterations where requirements evolve and teams deliver some working fully coded and tested product increment each sprint. Agile encompasses values and principles of working that are realised in specific frameworks and practices.


What is Waterfall?


Waterfall is a traditional sequential approach to software development. Unlike Agile, where all software development stages are done within a single iteration so that a working software is produced at the end of each sprint, in Waterfall you have discreet project phases. Usually each project phase cannot be started until the previous phase is completed. For instance, you first do all the planning & analysis, then you start the design phase, when design phase is ready, you start the development phase, after that the testing phase and so on.


Reasons why Agile is better



01. More flexible planning


In Waterfall requirements are usually ''frozen'' at the beginning once the planning phase is completed. The problem is though that it is impossible to gather all requirements upfront and whatever requirements you do gather are guaranteed to change. There'll always be something that users or developers will not think of at the start of the project or until they see how the system takes shape regardless how hard you try to create an ''ideal'' plan.


Agile teams, however, plan frequently and plan just enough for current and following sprints. The further something is expected to be developed, the more high level you approach it during the planning. Feature priority dictates how detailed the planning has to be.


Unlike Waterfall, Agile welcomes changes. The possibility of updating the plan and priorities is embedded into Agile process. Change control process is very burdensome in Waterfall.


02. Better quality


There is a significant quality risk when it comes to Waterfall. Think of it the following way.

When development stage is behind schedule, teams are prone to cut their time for testing stage and hence they might fail to reveal some potential bugs in the system.

In Waterfall you have one big piece of functionality usually delivered at the very end of the project. Testing big features all at ones might require additional time and efforts and might be less effective.


With agile you deliver granular pieces of functionality each sprint. They are fully done meaning you have also tested them within the sprint to ensure they're of high quality according to your definition of done. So there's something potentially shippable each iteration unlike Waterfall where the solution is delivered once at the end.


03. Smaller hand-offs


By eliminating hand-offs we eliminate problems created by waiting and by the need to transfer knowledge from one person to another. As Waterfall project phases are discreet and sequential, the output of each group (design, development or testing group) might become quite large. Agile eliminates this issue by overlapping all software development stages as much as possible within a single sprint. Hand-offs still exist, but they're not as big as in Waterfall. For instance, testers start quality control as soon as possible even when the product backlog item is not yet completely ready by working closely with developers.


04. Right product


Each iteration Agile provides mechanisms to review the product you've built. On a sprint review you gather stakeholders and show them the working software. You gather feedback and then based on it you adapt your product. You're able to pivot and change your priorities when and if needed assuming your previous assumptions regarding the product were wrong.

That's why Agile, and Scrum in particular, is an iterative approach to developing software that allows to share the results as soon as possible with clients and customers, receive valuable feedback and ensure you're still building something your users need and will use.


If you're using Waterfall, you'll probably get a final working solution at the very end of the project. That means there'll be no chance to learn if you're still moving into the right directions and incorporate your user's feedback. As a result, you run into the risks when your product might not solve user's real problem as initially predicted or it's just not user friendly.


05. Better predictability


As you already know, Waterfall is a sequential software development process where you do all the planning upfront. That can lead to a misconception that Waterfall provides more clarity earlier on how big the project is going to be, how much time it's going to take etc. It might seem that by spending extra time on planning at the beginning, you'll figure everything out. You're happy with your plan and ready to kick-off the project. However, don't fall into this trap. It's impossible to predict the future. Waterfall projects almost always are behind schedule as estimates team has made are not accurate.


Agile focuses on removing uncertainty within initial sprints of the project. First iteration goals are to learn more about the technologies being used, the product and its goals, even learn more about the team if it's a completely new team. So agile teams would spend these initial iterations to get some history of working together so they can leverage this historical data and understand their velocity (how much work they deliver on average during a sprint). Then they use this data to plan future work and make it predictable.


Agile software development factors in uncertainty and tries to reduce it which is the main goal at the start of the project. Agile teams might not give ''accurate'' estimates at the start but eventually they'll be more predictable comparing to Waterfall teams with traditional approaches.


Conclusion


Waterfall sequential process to project management might be an option for short-term projects (1-3 months) where the end goal is clear and the uncertainty is very low. Agile approach would work best though for all long-term projects with higher degree of complexity. Agile approach is more flexible at planning, provides mechanisms to ensure higher product quality, eliminates or reduces hand-offs within the team, allows to be more predictable in the long-term and, last but not least, is about building the product that will bring value to real people by embedding the constant feedback loop.


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P.S. Looking for additional guidance on Scrum framework as a whole? I’ve created Agile Scrum Master training course for beginners with everything from A to Z needed for you to succeed with Agile.


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