Agile has become the go-to approach for many software projects today. But it’s important to remember that Waterfall isn’t an outdated methodology – it’s simply a different approach to developing projects.
There’s no one-size-fits-all solution in the world of software development. You need to take into account the scope of your project, your timeline, your resources, and your own availability. The last factor is especially important because Agile calls for more client feedback and engagement than Waterfall.
In this post, we’ll take a deeper look at each methodology and its pros and cons to help you make an informed decision. Let’s start with Agile.
The Agile Software Development Methodology
At its core, Agile is a set of principles for developing better software in today’s fast-paced world. As its name suggests, it promotes agility, which in this context means the ability to continuously adapt and make improvements in order to optimize results.
Agile won’t tell you exactly what to do and how to do it. Instead, it will give you a set of guiding principles that will determine the development course for your project.
There are multiple approaches to implementing Agile, including:
- Scrum – An iterative approach that uses Sprints to deliver software in weekly cycles. With Scrum, developers continuously test, analyze, and request client feedback.
- Kanban – A visual framework that uses cards to manage the flow of features, Kanban is not iterative but incremental. It follows the key stages in the manufacturing process.
- Extreme Programming (XP) – XP enables you to prioritize the development of features and prescribes engineering practices to drive the best results possible.
- Lean Software Development – Applied to software development, the lean methodology aims to reduce activities that don’t add value and focuses on developing, deploying, and testing one feature at a time.
The most widely used approach to implementing Agile is Scrum. When it’s integrated with Scrum, Agile breaks down projects into smaller, more easily manageable bits called User stories and prioritizes them.
The development team works on delivering User stories in Sprints or cycles ranging from 1 to 4 weeks. It builds software incrementally, instead of all at once. This approach allows you to provide feedback at the end of every Sprint as opposed to at the end of a longer development phase.
Analysis, design, coding, and testing are not one-off but continuous activities, and the development team integrates them into each iteration. Because of this, you enjoy flexibility and scalability. At the same time, you have the freedom to figure out some of the details along the way.
With Agile, you still have a route to follow and a destination to reach within a given timeline. But your development map doesn’t force you to stick to the common path. You can explore other potential routes along the way.
Agile Pros
- Enables a quick start
With Agile, you can get started on your project right away even if you haven’t gathered all project requirements or figured out all the features you want to be added to the final version.
- Allows for adaptive planning
You can cut or enlarge the scope of your project while it’s in development. If you’re not 100% sure about all features, you can test them along the way to see how they pan out.
- Can reduce development costs
You can add new features or remove features mid-project at a much better cost and without having to push your deadline too far back.
- Makes delivery more predictable
Because each Sprint lasts 1 to 4 weeks at most, you know when you can expect the next iteration. You are less likely to meet with delays that can bog down the entire project.
- Gives you an active role in the development process
With Agile, you can choose to participate in the development of your project in a way that is not possible with other methodologies. You can provide continuous feedback after every iteration. By doing so, you can help polish every facet of your product at every stage in its development.
- Can improve the user experience
With its emphasis on User stories and continuous testing, Agile promotes the development of features that users actually need instead of simply developing IT components.
- Reduces unnecessary documentation
Agile promotes face-to-face communication over documentation. It doesn’t eliminate essential documentation, but it helps you avoid unnecessary paperwork.
Agile Cons
- May cause delays
With Agile, you generally can’t quantify everything from the beginning – it’s the price you have to pay for its flexibility. If you don’t manage unquantified efforts carefully, you may create a longer development cycle.
- Could create a piecemeal effect
If requirements change later on in the project, integrating new features into the existing code can be more challenging. An Agile team needs to ensure all software components are well polished and work together perfectly. Otherwise, the software may feel like an aggregation of features rather than a cohesive product – it may lack fluidity.
- Requires more involvement
The quality of your feedback can have a big impact on an Agile project. Without proper feedback, it’s harder for developers to create a product that fully meets expectations.
The Waterfall Software Development Methodology
Waterfall is the traditional approach to building software. It’s linear and uses distinct stages for each phase of the development process.
Much like a real waterfall, it flows one way. It doesn’t change direction suddenly, nor does it broaden unexpectedly. Instead, it flows uniformly toward the last phase of the project.
Waterfall predates Agile, but that doesn’t mean it’s outdated.
- When you choose Waterfall, you have to provide all the project requirements right from the start and make them as clear and as detailed as possible.
- The development team will then get to work and start designing your software.
- Next, the team will code and do unit testing, before performing system and user acceptance testing.
- Lastly, the team will fix any issues that testing brings to light and deliver the final product.
This simple, chronological approach makes the entire development process very clear right from the outset.
On the other hand, it doesn’t leave much room for changes once development begins, at least not in an intuitive and cost-effective way. What’s more, you don’t get an actual piece of working software until late in the development process.
Waterfall Pros
- Provides a clear direction right from the start
The development team knows exactly what it needs to build. It can focus on creating the best possible design right from the start.
- Keeps project management simple
You know what the development team should accomplish after every phase so you can compare that against your goals.
- Allows for a hands-off approach
You can determine the course of the development right from the start and then not interact with the development team until the next review stage. The time between review stages will be longer than between Sprints.
- Makes tracking progress easy
Since you define the scope of the project from the start, you can easily measure progress during each stage. You don’t have to factor in the impact on mid-project changes on the final product.
- Helps you stay within budget
If you are going to stick to your initial requirements, staying within your budget will be easy. Final costs are less likely to fluctuate since you won’t be adding new features.
Waterfall Cons
- Makes initial requirements extremely important
You have to put together clear project requirements right from the start. If you’re embarking on a long-term project, you need to know your audience and possibly anticipate usage trends. Unclear requirements can lead to poor results.
- Can increase costs
As we’ve already noted, a linear approach to project development often increases the cost of implementing changes. Waterfall is more rigid than Agile.
- Leaves testing until last
Testing is a crucial phase of the Waterfall methodology. But because much of the testing occurs late in the development, problems may pass unnoticed at first. Revisions could then cause delays.
- Requires you to wait for working software
You get a working piece of software only after all the core features have been coded and tested. Your actual hands-on experience with the software can’t steer the direction of the development until the very last stages of the process.
The Bottom Line
Agile has some important benefits over the more conventional Waterfall methodology, including flexible development, adaptive planning, and a continuous feedback loop that can significantly improve the user experience. It’s ideal for dynamic, long-term, or ongoing projects where it’s simply not possible to know all variables at the outset of the process.
That being said, it’s important to remember that Agile is not a silver bullet for all software development projects. When you have many initial requirements, a fixed timeline and budget, and a clear scope, Waterfall can help you stick to your goals and keep things simple.
In the end, a good software development team knows how to take advantage of Agile’s benefits but at the same time understands when Waterfall is the more natural choice.
That’s why it’s best to approach software development methodologies with an open mind and choose between Agile and Waterfall for each individual project, rather than assume that one methodology is always the best for all projects.