Agile vs Waterfall: Key Differences and How to Choose the Right One

Software development can take on a variety of project management styles, with Agile and Waterfall being among the most effective. If you want to build a solid product within a set timeline with minimal roadblocks, you’ll need to choose the method that fits your project.

So, what’s the difference?

Waterfall projects take a linear approach — with predictable results. Sequential steps take you from one stage of development to another, so there’s never any confusion. Agile methods are iterative — circling back to develop on the same idea through various stages of feedback and testing.

Each method comes with its own pros and cons, which is why understanding these differences is critical for business owners seeking software development services.

What is Waterfall?

For a Waterfall model to work, you need two things: clearly defined requirements and a solid scope of work. 

This traditional, linear approach offers little room for argument or dispute, and only works for business owners who are starting a project with complete clarity.

Definition and Overview

This method will divide your project into independent, sequential phases. You’ll have to work through each step before moving on to the next. Phase one starts with data collection and clarifying the client’s needs and objectives. Once you’ve locked in the scope of the project, it cannot be altered at a later date. 

Next comes the design phase, where the team develops the blueprints. These are run past the client for approval before the team moves onto phase three, i.e., implementation.

The team works day and night to perfect the code, and once it's done, the build phase is complete.

Phases four and five are verification and maintenance, respectively. These include comprehensive testing both before and after deployment.

Pros and Cons of Waterfall

The Waterfall method appeals to many business owners because of its simplicity, and has a lot of advantages: 

• Milestones are well-defined and easy to manage, requiring less coordination

• The team operates on a strict schedule and doesn’t require constant oversight

• Locking in the requirements results in accurate cost estimates

• Because the scope of the project is clearly defined on Day 1, Waterfall teams are more likely to stick to their budget and timelines.

  
  

Leanware’s Fixed Scope engagement model mirrors these benefits for businesses who want to follow a linear process. By fully specifying the scope and timeline in advance, we ensure there are no unexpected deviations or hidden costs.

Waterfall’s drawbacks stem from its inflexibility and strict structure:

• It’s difficult to share progress while the project is ongoing

• Once a specific phase is complete, the transition between teams may cause delays

• Going back to previous stages to make changes is both difficult and expensive.

• A single missed deadline can have a significant impact on subsequent stages.

As a result, this method is highly discouraged for projects where requirements are likely to change. 

Use Cases for Waterfall

Industries such as healthcare, construction, and manufacturing can benefit from a Waterfall development method.

Since this approach relies heavily on extensive documentation, it provides traceable checkpoints that favor projects with strict regulatory demands.

Additional use cases may include government projects with well-defined requirements that require minimal feedback. Each phase can be approved upfront to ensure clarity among stakeholders.

What is Agile?

Agile workflows guarantee a quick time to market and continuous delivery! This flexible approach relies on small sprints, allowing teams to deliver code, gather feedback, and test their product at every stage.

Definition and Overview

Collaboration is the cornerstone of Agile strategies. Frameworks like Scrum and Kanban rely on a system of iterative cycles with continuous feedback loops. For example, in Scrum, a cross-functional dev team commits to a number of set milestones over a set period.

Pros and Cons of Agile

The Agile method appeals to companies that value flexibility and owners who want to take a hands-on approach to management:

• Since the work is broken into sprints, clients can offer consistent feedback

• Changes can be incorporated at any time, catching problems early on

• Time-to-market is incredibly quick, with rapid delivery of usable features 

• Prioritizes quality and value delivery over speedy project completion

Leanware’s Managed Team and Staff Augmentation models support Agile projects by allowing for shifting priorities and scope adjustments. We value client collaboration, and this approach allows frequent demos and reviews, so the teams are on the same page throughout.

The biggest drawback to Agile is its unpredictability: 

• Because it doesn’t lock down the scope up front, it's harder to predict the final cost and timeline

• Requires a cultural shift where teams need strong discipline and a willingness to make rapid decisions

Use Cases for Agile

Agile designs are tested early and built to suit the evolving needs of businesses. This includes startups, SaaS businesses, and B2C setups where user feedback plays a huge role.

In industries such as education or advertising, development teams can launch an MVP (Minimum Viable Product) to test the market and refine it in subsequent sprints. The Agile method also works well for research-intensive projects where developers need to pivot based on findings during the early launch process.

Key Differences Between Agile and Waterfall

Approach and Flexibility

A Waterfall approach is linear and plan-driven, meaning that every stage must be completed before the next one begins. This makes it difficult and expensive to go back and make changes to the code.

While it's ideal for reducing uncertainty and clarifying expectations, Waterfall methods don’t work well with last-minute changes.

In contrast, an Agile approach is adaptive and incredibly flexible. Its iterative approach supports short cycles of work, with frequent check-ins that allow constant oversight. This works well with product owners who are hands-on with feedback and market testing.

Teams can focus on providing real value and adjust milestones to align with shifting priorities.

Project Phases and Workflow

The phases in a Waterfall model look like cascading blocks with no overlap. Before one phase starts, the last one must end. That means delays in one stage impact the entire chart, and unforeseen blockers have a massive ripple effect. 

As Atlassian puts it, this creates a “use it or lose it mentality” that encourages developers and product owners to negotiate wide time frames for each phase.

An Agile approach employs a cycle of planning, development, testing, and feedback that repeats itself multiple times throughout the project lifecycle.

These cyclical sprints encourage collaboration and ideation, so teams have time to deliver small batches of features and incorporate feedback before proceeding.

Cost and Time Considerations

With a Waterfall project, you decide everything upfront. What is the team going to work on? How will they work on it? Which resources do you need for the project? How long do you need them? Every minute detail is discussed and documented long before the team begins working.

As a result of this strict planning, all the stakeholders involved have complete clarity about what is expected of them and can provide incredibly accurate budget and timeline estimates.

So, if you’re someone who values predictability, the Waterfall method has you covered!

It’s not unlike a train on a set of tracks. Once you start the engine, it will reach the decided destination - no detours, reroutes, or changes.

An Agile approach is a lot more flexible, leaving room for multiple iterations and for new information to reveal itself during the development process.

On one hand, this reduces wasted effort by making sure each release builds on the success of the previous one. However, it can increase management overhead and extend timelines as the strategy shifts.

How to Choose Between Agile and Waterfall

Waterfall vs Agile — how do you make this decision? What are the factors that you need to consider? The needs of your project will determine which project management style works the best. 

Evaluating Project Needs

• Requirements Clarity:

If the requirements are clear and unlikely to change, Waterfall’s structured phases are a good option. However, if you’re expecting them to evolve, as in the case of a startup MVP, Agile is a better fit.

• Risk Tolerance:

Highly risky projects with numerous unknown variables can also benefit from Agile’s incremental feedback to identify problems early.

• Project Complexity:

If you’re dealing with a complex project that has multiple interdependent stages, Agile’s looping system will align with your needs.

Considering Team Dynamics

• Collaboration Style:

Agile projects require a collaborative and cross-functional team that can make critical decisions when it comes down to the wire. Traditionally organized teams may be more comfortable following a Waterfall approach.

• Team Experience:

If your team is experienced with Scrum or Kanban and has a dedicated Project Owner, they’re better equipped to work on an Agile workflow. However, if your team is more specialized and used to following detailed instructions, Waterfall might fit better.

Aligning with Business Goals

There is a solid link between the methodology you use and the strategic objectives that are a priority for your project.

• Time To Market

Since Agile works on shorter development cycles, it has a shorter time to market. Features can be released and improved in later sprints, meaning you can deliver value faster. Waterfall projects have to run through every stage before the product is ready for market testing.

• Stakeholder Involvement

Agile thrives on active engagement from customers and executives every sprint. If they can’t commit that time, you may want to lean towards Waterfall.

Common Challenges and When Each Methodology Goes Wrong

When Waterfall Fails

The Waterfall method often breaks down when the requirements change after design has started. Since the model relies on a rigid timeline, even a single missed detail can cause major replanning.

Delays can accumulate at phase boundaries, so if one phase slips, every downstream phase is affected. Waterfall also struggles if team members are siloed and handoffs between various stages are not smooth.

When Agile Fails

The biggest pitfall for Agile workflows is scope creep. Without a firm end goal, the backlog can grow endlessly, derailing schedules and budgets.

Stakeholders who are hands-off can cause trouble too: if the Product Owner isn’t engaged, the team may build the wrong thing iteration after iteration.

Agile’s overhead (constant planning, demos, and deployment pipelines) is a waste if the team isn’t committed to delivering the working software each sprint.

At Leanware, we tailor our workflows and processes to support your project’s needs. From Agile to Waterfall methods  — contact our team directly to learn more about Leanware’s software development services.

FAQs

What is the main difference between Waterfall and Agile?

While the Waterfall approach works better for companies that have a well-defined linear process from the outset, the Agile method offers more flexibility for business owners who want to provide consistent feedback throughout the various phases of an iterative development process.