Agile vs. Waterfall: Which Methodology to Use?

Agile and Waterfall are two methodologies used in software development projects. Both have their advantages and disadvantages, so how do you decide which one is right for you?

In this article, we’ve provided a list of factors to help you make an informed decision.

What is the Agile Methodology?

Agile methodologies – of which there are multiple, but we will focus on the “Scrum” variant – are built on the idea of a self-organising, cross-functional team. This team develops a product using adaptive planning, evolutionary development, as well as early and frequent delivery with ongoing and transparent communication with all stakeholders. Simultaneously, there is continuous improvement using customer involvement and feedback.

As the name suggests, Agile is a very flexible and fluid method of working, where any change in direction or scope can be quickly implemented. This is because instead of working on the entire product in one go, the team develops the software programme in phases.

The process starts with a minimum viable product (the most basic version of the product that delivers bare-minimum functionality), and all subsequent iterations are built up from it. These iterations are delivered to the client – or Product Owner – at the end of each sprint.

A sprint is how the project’s timeline is divided, with each sprint lasting two to six weeks. The team decides on the tasks to be completed at the beginning of each sprint, including what product features they will develop and how they will test them. That means the product evolves, adapting to, and delivering on, the most important and valuable features at that point in the project.

It often means a product can be put into use before it’s even fully finished, so the project team can get early feedback from users.

What is the Waterfall Methodology?

Waterfall methodology is the traditional method of software development, where each phase is distinct and well-defined. The team completes each stage before they move on to the next.

First, they design the product, then develop it, and finally test the product once the development is complete.

The methodology is efficient, with each stage properly developed and documented. If the project were handed over to another team, they would not find it difficult to pick up from where the previous team left off because the planning and documentation is so comprehensive.

This does, however, mean that this methodology can be rigid. The planning stage is very distinct from the development stage, so there is not much room for manoeuvring once the product design has been finalised.

Typically, Waterfall is chosen where the buyer of the software has a clear specification and the developer/vendor/supplier needs to deliver exactly as required, often under a fixed price arrangement.

How To Choose Between Agile And Waterfall Methodologies

Agile – Best for large projects, requiring flexibility, but with an experienced team

Agile is a fluid methodology, so works better on projects where the desired functionality of the end-product is not fully known from the outset. In this case, the team starts a project with minimum features and usability, and builds upon it.

With Agile, the development process is usually more involved, so can be more expensive. Because of this, larger projects with bigger budgets will get better results using this methodology. Since they have a well-defined scope of work, the team can build additional functionality with each iteration until it completes the initial requirements specified by the client (or product owner).

Some products may need to be changed midway through the development process to accommodate changes in the requirements/market or a new technological development. For this reason, Agile is more suited where flexibility is needed, as this type of quick change in direction is nearly impossible with the Waterfall methodology.

With Agile, the client is able to see a basic version of the product fairly quickly, but this method requires much more customer involvement via feedback at the end of each sprint.

Agile teams are very flat in structure. While they do have a product manager and a product owner, the teams are not hierarchical. This means the developers get more freedom in the way they work, which makes it easy to get carried away with adding on features.

This is why Agile teams need to be very organised and disciplined, or the development team might find the scope of the project growing, making it difficult to meet deadlines.

Agile is a system that may look like it has no rules, but that is not true. Teams using Agile methodologies need to be well-trained, experienced, collaborative, and very disciplined. If they are, they will get results very quickly and efficiently.

Waterfall – Best for restricted timescales, precisely known functionality, minimal customer involvement and limited budgets

If you are not sure about your team’s efficiency, Agile might be a risky methodology to use. For an inexperienced team, the Waterfall system would give better results, due to its clearly defined parameters and timescales.

The Waterfall methodology is ideal for products that have precisely defined functionality. In this instance, the development team knows exactly what is required; they build it, test it, and deliver. Since this method relies on a crystal-clear project brief, with equally clear deliverables, there is very little potential for it to go over budget. This is why it works so well for smaller projects, or those with tight budgets.

With its clearly defined stages and timelines, the Waterfall methodology is also better for projects that are time-bound. On the other hand, the client won’t see the product until the very end. Since it does not require much customer involvement after the initial planning stage and the customer doesn’t see any results for a long time, poor communication can lead to an unhappy client who feels the project isn’t moving forward.

Conclusion

Waterfall is a good methodology that delivers results for small, well-defined projects running on a schedule. In contrast, it isn’t very effective for large projects or ones that might require flexibility.

Agile offers more advantages and is the preferred method for efficient software development. The only caveat would be that the team needs to be trained in the ways of the chosen methodology, experienced at working within the framework, and disciplined. If this is not the case, a project could get out of hand, get delayed, or go over its budget.