If you are an application developer, you probably have heard of agile and waterfall development methods. But do you know how to differentiate them and when to use them? In this article, we will explain the main features, benefits, and drawbacks of each approach, and give you some tips on how to choose the best one for your project.
Waterfall development is a linear and sequential process that follows a predefined set of steps from planning to deployment. Each step must be completed and verified before moving to the next one, and there is little room for change or feedback along the way. Waterfall development is suitable for projects that have clear and stable requirements, well-defined scope, and predictable outcomes. However, it can also be rigid, inflexible, and risky, as it does not allow for testing or validation until the end, and it can be difficult to adapt to changing customer needs or market conditions.
Waterfall works step-by-step, finishing one thing before starting the next—like climbing down stairs. It sticks to a strict plan made at the start, making changes tough as it goes along. Agile is more like trying small steps and adjusting as you go, allowing changes whenever needed. It's like building with Lego, where you can change pieces easily. Agile encourages working together and getting feedback often to adjust plans quickly.
Agile and Waterfall are divergent software development methodologies. Waterfall follows a linear, sequential path, completing each phase before moving on, suitable for projects with stable requirements. In contrast, Agile is iterative, delivering small increments in short sprints, allowing flexibility and adaptation based on feedback. Agile embraces change, while Waterfall is rigid once initiated. Team dynamics differ, with Waterfall often hierarchical and Agile emphasizing collaboration. Choosing between them hinges on project nature and flexibility requirements.
Like constructing a tower block, waterfall development builds systematically floor-by-floor; changing the foundation late causes instability. Success depends on strong upfront planning and design. As the enterprise architect, I enable this by facilitating thorough analysis of business needs, auditing technical capabilities, and governing architectural standards.
No software is going to have a 100% clear requirement from the start. Whether you’re choosing Agile or Waterfall, make sure you’re clear on vision of software product and have at least 70-80% of the items that will make up the core of your product figured out, discussed or on the table before you begin. Based on each iteration, decide on the core item you’d address and give ample time to delve deeper into it, address its problems and find solutions, create documentations in detail if you have to(you always should). Then break it down into digestible chunks for team and whatever model of development you chose. This gives you freedom and flexibility to switch a dev. model and lets you focus on actual development of the product.
Agile development is an iterative and incremental process that delivers working software in short cycles called sprints. Each sprint involves collaboration, feedback, and testing among the development team and the stakeholders, and produces a potentially shippable product increment. Agile development is suitable for projects that have dynamic and evolving requirements, uncertain scope, and complex problems. However, it can also be challenging, demanding, and chaotic, as it requires constant communication, coordination, and flexibility among the team members and the customers, and it can be hard to measure progress or quality.
When measuring progress, I have to reference one of the 12 principles from the Agile Manifesto - "Working software is the primary measure of progress.". So, with no or limited working software we have limited progress. On the quality part, quality is difficult to measure unless you have gatekeepers and strict policies on what's expected from the work... but those expectations might be someone's opinion (so who said that those things are always right). They might also be relevant for when they were created since the software is an evolving field. Given that the "quality" attribute might be better benchmarked on a case-by-case basis, per team.
Like a race car pit crew, agile development demands smooth collaboration between cross-functional squads; my role as enterprise architect is providing the garage and tools for rapid iterations. I enable this by fostering a DevOps culture, implementing lean architecture practices, and evangelizing value-focused mindsets over perfectionism.
The key differences between agile and waterfall development can be summarized in four aspects: planning, execution, delivery, and change. In waterfall development, planning is done upfront and in detail, execution is linear and sequential, delivery is done at the end and in bulk, and change is avoided or minimized. In agile development, planning is done continuously and adaptively, execution is iterative and parallel, delivery is done frequently and incrementally, and change is welcomed and embraced.
Both agile and waterfall development have their pros and cons, depending on the nature, size, and context of the project. Some of the pros of waterfall development are: clear and consistent expectations, easy management and control, low dependency and overlap, and high documentation and standardization. Some of the cons of waterfall development are: long and costly cycles, late and limited feedback, high risk and uncertainty, and low customer satisfaction and value. Some of the pros of agile development are: fast and frequent delivery, early and continuous feedback, high responsiveness and adaptability, and high customer satisfaction and value. Some of the cons of agile development are: vague and changing expectations, complex management and coordination, high dependency and overlap, and low documentation and standardization.
There is no definitive answer to which development method is better or worse, as it depends on various factors such as the project goals, requirements, scope, budget, timeline, quality, team, and customer. However, some general guidelines on how to choose the best one for your project are: use waterfall development if you have a clear and fixed vision, a well-defined and stable scope, a long and predictable timeline, a high-quality and low-risk product, a large and formal team, and a passive and distant customer. Use agile development if you have a vague and flexible vision, a dynamic and evolving scope, a short and uncertain timeline, a functional and innovative product, a small and collaborative team, and an active and engaged customer.
Something to note. There can also be an overlap of an agile and waterfall project. Agile with mini-waterfalls For instance, the whole project can be set to be done in agile but each phase of the project can have a lengthy review, documentation and testing stage like in waterfall, depending on how much the PM wants to minimize changes or standardize the requirements upfront
Don’t get caught in a trap where an agile approach gives you permission to never finish. Bring a clear vision of what done looks like.
The aging model isn't a recognized term in software development, but assuming you meant Agile, it prioritizes flexibility and collaboration, adapting to change iteratively. In contrast, the waterfall model follows a strict, sequential process from requirements to maintenance. Agile fosters continuous feedback, while waterfall is rigid and may face challenges with evolving requirements. Differentiate them by considering adaptability (Agile) versus a structured, linear approach (waterfall).