Agile vs. Waterfall: Strengths and Weaknesses

Waterfall design methodology refers to linearly developing a business process with changes arriving at a steady pace from higher-level functions. In contrast, Agile design methodology encourages a constant flow of new ideas from designers and engineers.

Waterfall-based businesses develop a monolithic, slow-changing product successively, with incremental changes introduced in phases at intervals determined by the upper levels. In Agile-based companies, there is a constant flow of ideas between all the organization levels, with the developers and designers challenging each other, sharing ideas, working together, trying out ideas on computers or prototypes, and offering various alternative solutions in the process.

Post Graduate Program in Agile

With University of MassachusettsView Course
Post Graduate Program in Agile

Each approach has its strengths and weaknesses. This article discusses both.

Table 1. Strengths and weaknesses of Waterfall and Agile

Waterfall

Agile

Area

Strength

Weakness

Strength

Weakness

Requirements

Relies on a complete and comprehensive requirements definition

Business requirements can change during the development process and can disrupt the requirements definition or be deferred to a next release

Rapid prototyping reflects requirements as they change and accumulate

Project manager takes on more responsibility for co-defining business requirements

Resources

Project managers can plan out required technology, finances, and personnel for the entire project

Shortfalls in any resource (such as failure of a technology to perform or delays in supply) can throw the project off course and lead to missing schedule and/or budget targets

Project managers adapt each development sprint to the available resources

Visibility into the overall project schedule may be reduced by variability in each sprint

Testing

Testing tailored to each defined product module

Tests are difficult to adapt to changing requirements and releases

Continuous and automated testing helps keep the development focused on ultimate requirements

Requires resources for test engineering and automation to keep testing on pace with development

DevOps compatibility

Suitable for slow- changing products that do not need Continuous Integration/ Continuous Deployment

Incompatible with Continuous Integration/ Continuous Deployment

Compatible with Continuous Integration/ Continuous Deployment

Requires a commitment to DevOps methodology and tools

The Flow of Requirements Between Business and Designers

In Waterfall project management, there are potential pitfalls like incomplete requirements; Waterfall project managers must bring all criteria to design and align them with business goals. Since Waterfall project managers align needs with businesses, they make sure that requirements are consistent and seamless. All Waterfall projects start with the project manager's requirement to identify the project's business goals and requirements. Designers meet this requirement, and they align the needs with business goals. When business goals are not met, designers bring more details to design to ensure the business goals are met. Sometimes, Waterfall projects are over-budgeted because of the design specifications that the designers do not meet. It is not the obligation of the business to identify and align requirements. This misalignment is another area where Waterfall project managers tend to lose track.

Agile project management adds a set of tools that will help the project manager identify requirements. It is the responsibility of the project manager to determine requirements. It is more common for Agile project managers to present requirements to the business, though this is not the project manager's obligation. Agile project managers can also delegate this to designers.

Waterfall project managers make sure requirements are correctly executed and are aligned with business goals before design work starts. Agile project managers work with developers and designers to build prototypes. They can also work with business stakeholders to review and ensure requirements are accomplished in a process that considers the entire business and moves in a waterfall-agile continuum.

Waterfall project managers can spend much time determining requirements and aligning them. Also, they can get stuck with technology requirements or financial issues and cannot deliver as quickly as they could in an Agile project. 

While Agile project managers also bring in technology and financial requirements, they are tasked with ensuring the conditions are executed in a fashion that will meet the business's needs in a waterfall-agile continuum. Agile project managers are responsible for building tools that allow the project managers to work closely with developers and designers, including the user experience team. As part of Agile project management, it is the managers' responsibility to report on their effectiveness.

Waterfall project managers are responsible for making sure everything happens promptly to always keep the project on track. The waterfall project manager's focus is to deliver solutions in a reasonable amount of time, even if that means it is more costly. Agile project managers also keep track of how long each task is taking, but their focus is on delivery schedules rather than task schedules. 

Agile project managers are also more prepared to take on change. When they enter into a project, they already know what tools they want to build. They also have a testing system in place to incorporate feedback as soon as it is received.

DevOps and Continuous Integration

The methodology of DevOps is based on Continuous Integration and Continuous Deployment. Continuous Integration, or CI, is a form of software development where all software developers and testers communicate with each other as they build software. In essence, CI is a communication channel between development and testing teams, and it requires a great deal of communication. At the end of the project, the CI developer needs to be the same person who wrote the code, and the QA team needs to work in the same location as the development team. Also, all test code, test cases, etc., have to run in the identical environment. CI is usually done in an environment that runs Docker. This method allows a developer to specify a series of steps for all of the builds to take place simultaneously in a unified way. The computer will build the application after each pass of the test case. Today, many CI tools on the market can take CI for large projects. One such tool is JFrog, which we discuss in a later article.

Continuous Integration software is usually used in production, which is the case for Web application projects. A developer can write code and test it locally in the same environment they created. CI speeds the feature release cycles of Web application projects. Feature releases are a way to introduce new functionality or enhance existing functionality to benefit the customer. A feature release should be in sync with the software roadmap.

Agile Scrum Master's Course (FREE)

Become an agile scrum pro with the free courseEnroll Now
Agile Scrum Master's Course (FREE)

Test automation is the method by which development teams can automate software testing. In other words, automation is the process of writing tests that test features. As development teams move to an Agile model, they adopt different automation methods, such as microservices testing and continuous integration. Test automation will add structure to an Agile organization, which will help all teams in an organization with Agile development. Test automation gives developers a way to focus on their code and development instead of testing. In a Waterfall model, developers can be forced to spend time running tests, which slows down developing a software product and can be considered a waste of time. At the same time, Agile teams face the constant challenge of adding features to a product. As such, testers need to be available and in front of the developers. Test automation can provide a solution.

The challenge for many teams is to understand what is the best delivery option: Waterfall or Agile? As more business processes are modernized through digital transformation, I firmly believe that Agile is the most efficient delivery model. Through the DevOps methodology’s Continuous Integration and testing, you can provide the highest quality code.

Test your understanding of the Agile concepts with the Agile and Scrum Practice Test. Try answering now!

Conclusion

We hope this article gives you a very practical understanding of the strengths and weaknesses of Waterfall and Agile. Both of these methodologies are highly popular business process and project management methods that have yielded phenomenal results for businesses world over.

If you are looking to gain advanced expertise in these methodologies along with a comprehensive work-ready understanding of modern project management, Simplilearn’s PMP® Certification Training Course is an ideal way to start. This is aligned with the PMBOK 7th edition and offers you not just fundamental knowledge in project management but also the requisite training you need to clear the PMP exam in 2021.

For a more in-depth exploration of project management, Simplilearn offers the Post Graduate Program in Project Management in partnership with UMass Amherst. To explore how these project management methodologies apply in modern software development and production, look into the Post Graduate Program in DevOps in partnership with Caltech CTME.  Do explore these courses and programs and begin your career ascent today.

About the Author

Matthew DavidMatthew David

Matt is a Digital Leader at Accenture. His passion is a combination of solving today's problems to run more efficiently, adjusting focus to take advantage of digital tools to improve tomorrow and move organizations to new ways of working that impact the future.

View More
  • Disclaimer
  • PMP, PMI, PMBOK, CAPM, PgMP, PfMP, ACP, PBA, RMP, SP, and OPM3 are registered marks of the Project Management Institute, Inc.