Agile software development is a strategy that emphasizes iterative processes, as well as collaboration between multiple teams or stakeholders. Although the agile methodology is now relatively dated, it remains important as the foundation for other widespread practices, such as DevOps and Site Reliability Engineering.
Agile software development originated in the early 2000s, when a group of developers issued the “Agile Manifesto.” At the time, software development tended to be slow, and projects commonly missed development deadlines. The agile methodology aimed to correct these issues by promoting what its advocates saw as a more efficient, faster approach to the creation and deployment of software.
How Does Agile Software Development Work?
Agile software development is founded on two main principles: iteration and collaboration.
Iteration allows developers to break complex software development workflows into smaller, more manageable parts. Instead of setting large development goals -- such as the release of an extensive set of new application features a year into the future -- developers focus on implementing the new features one by one, over a short timeline. As a result, the application evolves iteratively.
When the agile methodology emerged, iterative development presented an alternative to the “waterfall” development model, which predominated at the time. The waterfall approach calls for releasing major software application updates on an infrequent basis. Thus, the development pattern resembles a series of waterfalls, with application functionality remaining unchanged until it receives a major set of updates.
The waterfall approach can create challenges for developers. It’s usually harder to set a realistic timeline for implementing a broad set of new features than it is for implementing individual features. In addition, because new features are often dependent on one another, problems that arise in developing one feature can cause delays in the development of other features, thereby muddying the entire development process.
Waterfall development can be problematic for users, as well. Users typically have to wait long periods for the application updates they want. They also can face major learning curves when updates do arrive, because the application will have changed significantly with little to prepare them in advance.
By prioritizing iterative feature update cycles, agile development aims to make life easier for developers, while also enhancing the user experience.
Agile development’s emphasis on collaboration reflects an effort to ensure software updates meet stakeholders’ needs.
Prior to the agile movement, developers would typically decide which software features to implement with limited feedback from the users -- or from the IT engineers responsible for managing the software. As a result, developers sometimes implemented features that were of little value to users and/or made applications difficult to manage for IT teams.
Agile aims to avoid these problems by encouraging close collaboration between developers and other stakeholders. Agile doesn’t go as far in this respect as DevOps, which explicitly prioritizes close collaboration between developers and the IT team and promotes specific processes for enabling collaboration, such as CI/CD. Still, agile emphasizes collaboration as a general principle, and agile thinking is often seen as a precursor for the DevOps movement (which emerged in the later 2010s).
What Are The Benefits and Drawbacks of Agile Software Development?
As noted above, the main benefits of agile software development include the following:
- Manageable application update cycles, which reduce the risk of delays;
- Fast application enhancements for users;
- Gradual change with each application update, which reduces the learning curve for users;
- A strong ability to implement features that stakeholders find valuable; and
- Enhanced alignment between developers and IT teams.
Arguably the greatest disadvantage of agile software development is that it requires significant effort to orchestrate. Planning iterative update cycles takes more work than it does to identify a large amount of features to implement over a broad timespan. Likewise, collecting feedback from various stakeholders is more labor intensive than allowing developers to decide what to build on their own.
In addition, agile development teams can fall into the trap of constantly implementing minor new features that never add up to meaningful application change. In other words, it can be difficult to build a totally new version of an application because teams focus on small, iterative updates instead of major overhauls. However, developers can avoid this problem by figuring out how to achieve major development milestones via small changes, rather than implementing new features on an ad hoc basis without a long-term application roadmap.
Examples Of Agile Software Development
Agile software development has a variety of real-world uses. Here are several below.
Moving From Waterfall To Agile
The classic use case is to migrate from a waterfall development process to an agile one. By now, many teams have already made this leap. But for organizations that still rely on slow release cycles and/or lack strong collaboration between developers and other stakeholders, the transition to agile is a key step toward overall modernization.
Refactoring A Monolithic Application
Agile development can help to refactor so-called monolithic applications (meaning those that operate as a single process and are based on one codebase) to a microservices-based application. Microservices applications breaks application functionally into discrete services, each with a separate codebase. While developers could theoretically build a microservices app without using agile, an agile approach makes it much easier to update each microservice individually to change the application iteratively.
Transitioning To DevOps
Agile software development isn’t the same thing as DevOps. DevOps requires specific processes, like CI/CD, whereas agile is more of a philosophy than a specific methodology.
Nonetheless, agile emphasizes many of the same core principles as DevOps. As a result, developers often use agile as a stepping stone toward DevOps.
Building A Larger Team
Because agile development breaks complex development operations into smaller components, it is a useful strategy for organizations that are amid growth and need an efficient way of managing projects. A development team that consists of just a few coders may find success with a waterfall approach, but large teams may need agile to keep development operations efficient and manageable.
Organizations that embrace agile software development can often edge closer becoming more innovative and digital-first operations. By making development operations more flexible and efficient, agile helps teams take better advantage of digital resources and react more quickly to technological changes.
Agile software development may no longer be at the cutting edge, but it remains a foundational component of how many businesses approach software development and innovation. It’s also a critical stepping stone toward other modern development practices, like DevOps.