Our Guide to Waterfall Methodology in Project Management
Key Takeaways
Every day, tech companies and software houses work on projects of varying levels of complexity, adopting popular project management methodologies such as waterfall, Agile, Scrum, or Kanban or sometimes a mix of them.
The key to a successful software development project that is delivered and maintained on schedule and within a set budget is choosing the right approach that meets the project requirements and can match all stakeholder expectations. In this guide, we are going to look at how the Waterfall method works and find out if this classic project management methodology is a good fit for your business.
The Waterfall Methodology Background
The waterfall model has gained popularity as one of the pioneering structured software development methodologies for providing a step-by-step approach to building ready-to-use products. Dr. Winston Royce first introduced it in a paper published in 1970 titled “Managing the Development of Large Software Systems.” In the paper, Dr. Royce outlined a sequential software development process involving a series of distinct phases, with each phase building on the previous one linearly.
What Is the Waterfall Model?
The Waterfall Methodology is a traditional approach to project management that follows a sequential process. It is ideal for projects with well-defined scope, requirements, and clear deliverables. The sequence of the Waterfall process is as follows; requirements gathering and analysis, design, implementation, testing, and finally, deployment. In the Waterfall Methodology, each stage must be completed before moving on to the next, and there is no going back to a previous stage.
The typical waterfall model consists of the following phases:
- The requirements phase is most often completed in collaboration with stakeholders to ensure that their needs are well-addressed.
- The design phase involves creating a detailed plan for the system’s functionality and how it will be deployed by the team members. System architecture and design are created based on the requirements gathered in the previous phase.
- The implementation phase is the stage where “actual coding” begins, meaning software development based on the design specifications. This phase involves writing code, creating software components, and integrating them into a fully functional system.
- Verification or testing phase – the solution is thoroughly checked to ensure it meets the project requirements and offers all necessary features as intended. Testing might include unit testing, integration testing, functional testing, acceptance testing, and more.
- Deployment and maintenance phase – once tests are complete, the system is ready to be deployed to the production environment, which involves installing the software on the production hardware, configuration, and making the solution available to end-users. In the final step, the system is monitored and maintained to ensure it continues working correctly. The maintenance phase may include bug fixes, updates, and other modifications.
Waterfall Projects vs. Agile Methodology
The waterfall methodology involves a far more formal, sequential development cycle in which detailed documentation, among other things, plays a significant role. This project management approach makes the execution process much less complicated and often is associated with specific financing from the beginning. A predetermined roadmap provides more stability, so it works well for teams with less extensive experience.
The traditional waterfall methodology works well when a client has a fixed budget, and a more predictable schedule is necessary for upfront product launch planning. Simple, long-term projects with a short list of requirements can be successfully developed this way. Typically, the waterfall process is highly recommended for companies that cannot afford sudden changes and the associated risks. Choosing a waterfall approach is also reasonable when clients have limited resources and cannot participate in ongoing consultations.
This is why the waterfall model is often compared to an agile project. One of the key differences between the two approaches is that waterfall requires everything to be written down and described in the documentation before any coding is done. All starting points must be considered from the very beginning, as it may take more work to revise them later.
On the other hand, within the agile methodology, subsequent activities are planned based on current events in iterations (sprints) lasting several weeks. One sprint leads to the implementation of the next element. At the same time, each work result is tested right away. Team members using the agile method operate in a constantly evolving environment, so they must flexibly adapt to project goals and related challenges.
The main characteristics of waterfall methodology:
- If the product requirements have changed after the agreement, the customer must report this formally and revise the task list.
- No iteration – there is one unified and transparent process for software development.
- Correcting errors ad hoc, is acceptable only during the testing phase.
- The customer is uninvolved in the process after the list of tasks and requirements is determined.
Key Principles of Waterfall Project Management Methodology
Project managers must follow a few rules to ensure that all team members consisting of frontend and backend developers, graphic designers, UX & UI specialists, and testers, operate efficiently and deliver the final product on time. Careful planning is a must, but understanding & defining customer requirements upfront and correctly estimating the project scope is essential.
- Prepare detailed documentation of each phase of the waterfall process thoroughly and get stakeholder approval before moving forward.
- Eliminate all possible external factors that can affect any sudden changes during each stage of the waterfall lifecycle.
- Spend as much time as needed in the design phase to ensure the architecture is correct before heading to software development. This approach will prevent an enormous amount of change requests later on.
- Complete the development process and ensure every element of the design works before moving on to the testing phase.
- Don’t spare time and resources for testing.
Pros and Cons of Waterfall Project Management Methodology
| Waterfall Model Advantages | Waterfall Model Disadvantages |
| The main advantage of the waterfall methodology is the reduced risk of failure in case of contractual restrictions (e.g., execution time, limited budget), especially relevant when delivering projects for the public sector. | A significant drawback of this approach is delivering a functioning product only at the end of the waterfall lifecycle. There is little room for user feedback. Such an important issue can cause the end result to differ from what the customer requested. |
| The waterfall model is clear and straightforward, and it is easy to understand and implement. It requires minimal resources, and its structure makes it relatively simple to track the progress of a project. | Software development with requirements that aren’t dynamically changing through all phases is a rare luxury. Reality shows that plans and milestones often get redefined, and the waterfall methodology works best for stable projects where the end goal is clearly set from the beginning. |
| Due to the inflexibility of the waterfall method, product development proceeds quickly, and the cost and timing are predetermined. | In the design phase, costs are relatively low, but they increase as you move to the next phase of a waterfall project. This is why upfront planning and ensuring the project manager is on the same page with stakeholder expectations are vital. |
| It is a perfect match for managing a large group of software developers – new team members can determine which development stage the waterfall project is in without much context. | Making changes in the later stages of a waterfall lifecycle can be challenging, due to its rigid and sequential nature. Unfortunately, modifications must wait until the cycle has reached completion before being implemented. |
| The waterfall model requires extensive documentation, which can help improve project transparency and facilitate knowledge transfer between new team members. | The waterfall method does not encourage cooperation and communication between different teams working on the project, which might lead to miscommunication. |
| The next stage starts once the previous phase is finished, and there is no way to skip any of the steps, making the waterfall methodology an ideal approach for project team members who prefer structured work to give their best. | Changes to the project scope, client requirements, or design must be carefully evaluated to ensure they don’t cause delays or budget overruns and that overall project goals are still met. |
What Kind of Projects Are Best Suited for The Waterfall Model?
After analyzing all the pros and cons,we can see that the waterfall approach works best for predictable software development projects with a clear scope and well-defined requirements, and the uncertainty about the final product is close to zero. Without meeting these criteria, project managers may struggle to identify and mitigate tech issues, which inevitably leads to delays, rework, and increased costs if new demands emerge. For a successful project, it’s also crucial that every team member is proficient in the chosen tech stack to build an end-to-end solution.
Examples of projects that are well-fitting for the waterfall methodology:
- Small-scale software development projects, such as off-the-shelf mobile applications or a responsive web design.
- Products with a well-established and defined set of requirements that are unlikely to change during the development process, such as building an accounting system or a payroll management system.
- Projects that require a detailed and comprehensive plan, such as in the construction industry, where the entire process is mapped out from start to finish, and each phase is executed in a sequential manner,
- Solutions that have a well-established project management process, where the team members have experience working with the waterfall model and can efficiently manage and track progress throughout the whole lifecycle.
Summary and Forecasts
Undoubtedly, choosing the right project management methodology is significant for further success. Consider what your customer’s expectations are. Do you anticipate a changing environment or stable development process? Are your team members familiar with the technologies, and do you have experience in similar implementations? Does the contract allow for any variations?
Whether we are talking about agile or waterfall method, no project will be successful unless there is adequate stakeholder involvement.
In the future, the waterfall model will likely continue to be used for well-thought-out projects. However, more agile development methodologies are likely to be preferred for complex software products that require flexibility and collaboration with investors.
Another factor that may shape the future of the waterfall method is the rise of low-code and no-code development platforms, which make it easier for non-technical users to create software applications without the need for extensive coding or development skills. These platforms typically follow an agile approach, allowing users to iterate and make changes to their applications quickly and with less effort.