Agile vs Waterfall: Know the Difference

Agile or Waterfall? That is the question! Learn the difference between the two distinct methodologies and pick one that suits your project most.
Masooma Memon
June 2, 2022

​​Looking to manage projects better at your agency? 

There’s no one scripted framework that’ll suit all your projects and team working style. That’s why knowing the difference between agile vs waterfall project management models is the key to understanding what is best for you.

In several instances, you may even have to work with one project management methodology over another depending on the project timeline, budget, project nature, and customer involvement.

Want to understand what is the right model for you?

We’ve the answer for you in this guide as we look at what each model is about, their pros and cons, and how to choose between agile and waterfall. For this last point, we’ve also talked to an expert who shared a chart to help you identify the project management model to use.

Read on!

What is agile methodology?

Agile is a project management methodology that breaks down projects into short cycles based on rapid production and constant iteration (revision). 

In doing so, agile team members focus on the process of planning, executing, and evaluating. 

Say a team is developing an app, for example. Using the agile method, they’d start off with planning, reviewing the plan, and revising it as necessary. Once approved, the development team would create a minimal viable product (MVP), test it, revise it, and repeat.

In this sense, agile development is focused on the following four core values:

  • Individuals and their collaboration weigh more than processes and tools
  • Working software is preferred over comprehensive documentation
  • Customer/client collaboration is more important than contract negotiation and
  • Responding to change is more important than following a plan

Essentially, this methodology originated in the software development industry as a new way to manage developing software.

Since then, other industries have welcomed it with open arms with the pandemic accelerating its adoption. In fact, a 2021 survey reveals that agile’s adoption rate has increased not only in software development and IT but also in non-IT departments such as marketing and human resources.

agile adoption
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Benefits of agile methodology

According to Organize Agile’s survey, companies say the biggest perk of the agile methodology is the flexibility it improves. Other benefits include improved financial results and a more productive culture among others.

benefits-of-agile
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Let’s look at these and other benefits of agile in detail:

  • Improved adaptability

Agile is focused on flexibility, encouraging entire teams to be responsive to change, even when it comes to last-minute changes. Project goals are consistently updated, and teams manage clients’ expectations and changing requirements effectively.

  • Satisfied clients

Agile team members are in constant touch with their clients — sourcing their feedback during various project phases. This shows the client that the agency working with them values their opinions and consistently implements feedback, boosting their satisfaction.

  • Improved quality

A core principle of the agile methodology is the focus on improvement, which naturally improves quality. In fact, each iteration is a step toward better quality. 

  • Reduced risk

With each iteration, issues are resolved. This increases the odds of success and mitigates risks, ultimately delivering a product that’s high quality.

  • More chances of learning

Again, due to its iterative approach, the agile methodology offers teams lots of chances to learn. Team collaboration and communication with the client also improve, helping managers build a high-functioning team that learns regularly from feedback and action.

Cons of agile methodology

The agile model shows some drawbacks too. These include:

  • Unpredictable project pipeline due to a lack of processes

It can be challenging to track and predict progress using the agile methodology. This is mainly because an agile team keeps working on a project as feedback comes, leaving little to no room for creating a dedicated schedule that dictates how much time to allot to a task. 

  • Poor resource planning

Agile is centered around teams not knowing what the final outcome would look like.  They also can’t tell how many iterations cycles a project would take. As a result, it becomes difficult to predict resources, time, and cost.

Learn the do's and don'ts of agile resource planning here. 📖

  • Scope creep is common

The lack of a clear vision of the final product and poor documentation leaves space for scope creep. To add, clients need change consistently which can lead to a growing project development scope — something not agreed to originally with a client. In fact, changing client requirements can leave teams confused — unsure about what to prioritize.

  • High time demands

On the surface, it may seem like agile is a time-saving project management methodology. However, the constant collaboration that it demands takes a lot of time. Team members need to manage their time not just for cross-departmental collaboration but also for meetings with clients, testers, and other project stakeholders. To add, such a high level of collaboration can add significant strain on team members’ workload.

What is waterfall methodology?

The waterfall methodology is a sequential project management methodology in which a project is broken down, arranged, and completed in a linear progression from the start to the end.

Because of its sequential nature, the waterfall model emphasizes thoughtful, upfront planning and detailed documentation. The project, in turn, is executed in stages that follow one after the other, only starting after the preceding phase completes.

For ease, the waterfall development model can be broken down into two main parts:

  • The analysis phase. It involves gathering client requirements to create user stories or user acceptance tests (UATs). These UATs, in turn, are used as project checkpoints where team members get signoffs from stakeholders to minimize major revisions down the line.
  • The implementation phase. With all the expectations set, the full scope agreed to, and documentation ready, this phase involves working on the project itself. 

Waterfall method benefits

Now for how this method is beneficial for managing projects: 

  • Effective time budgeting and cost estimation

Upfront research and detailed documentation on project requirements mean you can better budget the time that’d go into implementation. It also means you can better plan resources and costs that’d go into the project.

Pro tip: Use a powerful project management software to manage projects in one place. Use it to track time and resources going into individual projects too. Runn, for example, offers timesheets that track and automatically record time spent on a single project. It also creates comprehensive project reports that forecast how much profit, revenue, and costs your projects incur.

  • Easy to onboard and train team members

This is largely due to the heavy focus on documentation that the waterfall model has. With the documents ready, it becomes simple to bring a new member to the project team up to speed with the requirements, expectations, and deliverables. 

  • Defined outcome

Since the waterfall method agrees on the project scope from the get-go, clients can’t keep adding new requirements to the project. This saves from production delays.

  • Easy to manage

The waterfall methodology is also easy to set up, manage, and optimize. This is mainly due to the model’s defined structure where each project phase has clear deliverables and review processes in place. What’s more, project phases don’t overlap — adding to the management ease.

Cons of the waterfall model

Let’s look at the disadvantages of the model now: 

  • Harder to change course

Since you work on the project phases in a sequence, you’re unlikely to go back to make changes after the work is done in full. Meaning: waterfall offers little to no room for course-correcting should there a need be. 

To add to that, sometimes clients don’t fully know what they want — only realizing what they want later in the process. This can make it tougher to accommodate revision and new feature requests later on.

  • Exacerbates known project challenges

Since each phase in the waterfall method starts after the one before it completely wraps up, team members can’t move forward until issues in the previous stages aren’t fully resolved. Without effective project management, this can easily slow down team members.

Similarly, clients only see the final outcome after it's complete. This way, important issues can remain undiscovered until release (this is particularly problematic for verticals like software development, website design, and similar).

Agile vs waterfall: Key differences between the two

Now that you know the basics, let’s walk you through how the two management models compare.

  • Both offer varying degrees of flexibility

The major difference between agile vs waterfall models lies in the flexibility in their nature. 

Agile, on the one hand, is flexible and adaptable. It was created to make up for the drawbacks of the waterfall methodology with the aim to work faster and better accommodate changes in software development. 

Currently, 95% of 40,000 respondents in the State of Agile survey use the agile development method. 61% of them have been using it for more than three years.

But this doesn’t mean waterfall isn’t popular. It’s appreciated for its structured nature. While some may take it as rigid, others commend the waterfall model for the predictability it offers.

  • Both suit different project types

Thanks to the differences in their nature and how work is organized, managed, and completed under them, both models suit different project types.

For example, agile is better suited for client-facing work that involves lots of client feedback and approval. It also works well for projects with a flexible timeline and budget because agile supports a changing work schedule and budget. 

On the flip side, waterfall suits long-term projects that have defined work scope, budget, and a fixed timeline (think: work to be completed in a given month, such as four content pieces).

  • Differences in the way work is planned and executed

Agile methodology doesn’t involve too much of upfront project planning and documentation. Instead, agile systems are built in short timeframes called sprints. These usually last about one to three weeks.

Within a sprint, work is done in short iterations of one or two weeks each with each iteration starting with a round of analysis where the team decides what they’ll work on. 

From there, the team works on the project and runs tests on it to see how it’s working. This cycle continues until you meet your project goal (such as launching a new feature or product). 

Waterfall, however, divides work into six stages. These include requirements, analysis, design, implementation, verification/testing, and deployment and maintenance.

To elaborate, the project manager starts off by gathering and analyzing all project requirements, documenting all in one document that shares the project costs, risks, success metrics, timelines, and resources needed from the client’s end.

It’s also here that all work is broken down and assigned to different team members according to a set project schedule.

After this comes design or the work phase where team members work on their assigned tasks as per agreed deadlines. In the next stage, project managers take stock of work completed, testing it, or running requirements against the project brief. The specifics of what’s involved in this stage depend on the project itself.

And finally, in the last stage, managers share the completed work with clients.

agile vs waterfall

Agile or Waterfall? How to choose the right methodology

When deciding on which project management methodology to use, start with reviewing your project requirement.

Nicole Tiefensee, Runn’s Co-Founder and COO recommends using Stacey’s Complexity Model to this end.

“You might have seen this diagram before,” Nicole explains. “The y-axis gives an indication of the level of agreement you have over what is needed on a project (the requirements), while the x-axis shows the level of certainty you have over the approach (the tools and/or technology you use to implement the solution).”

 

Stacey's complexity model
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Using this chart, Nicole says, tasks or projects can be split into four categories:

  • Simple. Well defined and easily solvable tasks. You can use historical data to predict the future and repeat what works well.
  • Complicated. Some negotiation and compromise are required to understand what’s needed and how you are going to implement the solution.
  • Complex. The “what” and the “how” aren’t fully understood. This is often considered as a zone of high creativity and innovation.
  • Chaotic. Very high levels of uncertainty exist on all fronts.

Of course, not all projects can be simple or complicated. Instead, agency projects typically fall within a gradient of these four categories. So the first step is to identify your project’s nature.

For instance, projects can be highly creative, requiring innovative solutions involving work such as web design, brand strategy, or a software development project.

Projects like these clearly fall under the “complex category” as there are usually several moving pieces involved. 

“Neither the ‘what’ nor the ‘how’ can be fully understood at the outset of the project, which makes it very difficult to predict all the eventualities of the project and build out an accurate plan up front,” notes Nicole.

“Those kinds of projects really benefit from:

  • High-level collaboration and communication with the client. (If you have a client who doesn’t want to get involved – I’d steer away from the project if you can)
  • Short iterations and adaptive planning that gives you and the client lots of checkpoints to look at where the project is at and adjust where things are going based on new learnings.
  • A flexible scope, if you are working toward a deadline.
  • Starting with something simple that provides some value to the client, then building out the solution incrementally over time.
  • Focusing on high-priority items that provide the most business value first.”

All these project requirements can be easily met using the agile project management methodology.

“Note that implementing an Agile method doesn’t mean you won’t need a plan,” Nicole warns. “Your client will still want to know if you can deliver within the budget, and upon agreed timeframes. And you and your agency will still want to know who’s available to do the work or if the project will be profitable. The key is to do just enough planning, at the start and at regular intervals throughout the project to be able to answer those questions.”

Similarly, there are packaged offers such as SEO, content production, and social media management.

“They tend to sit in the ‘complicated’ terrain,” observes Nicole. “While there can be differences of what’s required from client to client, predictability on the ‘what’ and ‘how’ is a lot higher.”

“You might not be able to predict the outcome of the work and will have to set expectations with the client as to what can be achieved, but you’ll be able go through repeatable steps and set predictable milestones.”

Take an SEO project for example: 

  • Phase 1 - Audit and Keyword Research
  • Phase 2 - Keyword Testing
  • Phase 3 - On-page Optimization
  • Phase 4 - Off-page Optimization

Nicole adds, “Based on previous projects and your experience you will be able to plan out the work to a relatively high degree of certainty, which makes it ideal for a more plan-driven approach with clear deliverables and hand-off points between project phases.”

In such a case, the waterfall project management model can help provide the framework you need to execute the project. 

In conclusion

While the agile vs waterfall debate still rages on, there is no one answer. Instead, the correct answer depends on your project’s requirements.

Either way, the key is to manage projects efficiently. That is: whether you’re using the agile model or waterfall, make sure you’ve a system and a defined process to encourage team collaboration.

Fortunately, Runn is methodology-agnostic and serves as a central platform to manage all projects, assign tasks with deadlines to team members, and track and calculate project financials. In fact, it also gives you an overview of each teammate’s workload, strengths, and hourly rates so you can easily plan who to onboard for specific projects. 

Not convinced yet? Sign up for Runn for free today and see for yourself.

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