What is Waterfall Methodology?
The Waterfall methodology is an approach to project management that follows a linear, sequential process. This approach is popular in software engineering and is called Software Development Lifecycle (SDLC). However, product development is also utilizing this model.
The term “waterfall” refers to the flow of the project, where each phase cascades down to the next. It involves a detailed planning phase, execution, testing, and maintenance. And each phase must be completed before moving on to the next, with little to no flexibility for changes during the project.
Additionally, the waterfall model is known for its structure and predictability, allowing teams to plan and budget accurately. Furthermore, it can also be criticized for its inflexibility and lack of adaptability to changing circumstances.
Advantages
Among the advantages of the waterfall model are the following:
- Provides a way for large or changing teams to work together toward a common goal defined in the requirements phase
- Ensures a disciplined and structured organization
- Provides a simple method to understand, follow, and arrange tasks
- Facilitates management control and departmentalization based on deadlines
- Establishes good coding habits by defining first, then implementing design
- Provides easy access to early system design and specification changes
- Defines milestones and deadlines clearly
Disadvantages
However, the waterfall model has drawbacks, including its inflexibility and lack of revision opportunities. Some specific concerns include the following:
- Design flaws, when discovered, often mean starting over from scratch
- It doesn’t incorporate mid-process feedback from users or clients and makes changes based on results
- Delaying the testing until the end of development is common
- There’s no consideration for error correction
- The model doesn’t accommodate changes, scope adjustments, and updates well
- Work on different phases doesn’t overlap, which reduces the efficiency
- Projects don’t produce a working product until later stages
- Not an ideal model to use for complex and high-risk projects
When to Use the Waterfall Methodology?
The waterfall model’s planning and documentation can be helpful for efficient resource allocation, but its inflexibility may limit plan modifications. So, evaluating the project requirements is necessary to determine if the model is suitable. The following are some instances when a waterfall system would be a great choice.
Established Project Requirements
Waterfall management may be the better choice if you have a clear objective in mind for your project. However, suppose the end goal is unclear, and there are ambiguous requirements or potential changes in direction. In that case, other project management methodologies may be the best approach for you or your clients.
Well-Defined Project Tasks and Deadlines
The waterfall model is a structured methodology. Hence, this methodology is designed for businesses prioritizing meeting deadlines, some examples are the construction or manufacturing industry.
You Have Plenty of Time to Plan
Waterfall management requires significant time allocated to the first two stages. If you have enough time to gather requirements and plan, you may opt for the waterfall approach. However, utilizing other methodologies may suit those with time constraints.
Waterfall Methodology vs. Other Project Management Methodologies
Agile
Agile methodology has less emphasis on up-front planning compared to the waterfall model. It doesn’t aim for a perfect, step-by-step plan before launch. Moreover, Agile outlines high-level objectives, goals, and deliverables in a roadmap.
Agile teams adjust to the changing demands of the market and stakeholders during the project. A project is usually divided into iterations or “sprints” that last about a month or two, and the course is adjusted after each one.
Lastly, the Agile methodology involves internal and external stakeholders throughout the process and encourages self-organizing teams, which differs from the Waterfall method, which lacks this focus.
| Waterfall | Agile | |
| Implementation | Linear | Iterative |
| Detailed plan timeframe | Whole project | Typically 2-8 weeks |
| Stakeholder engagement | Mostly upfront | Throughout the entire project |
| Team structure | Traditional hierarchy | Often more self-organized |
| Main benefit | Consistent, reliable, and controlled outcomes | Adaptability to rapidly changing markets |
Kanban
The Kanban framework falls under Agile, emphasizing flexibility and constant adaptation. Unlike the sprint-based approach, Kanban prioritizes continual improvement using a “Kanban board.” It’s either digital or physical and consists of columns ranging from “to-do” to “done.”
You can add new ideas to the to-do column as ideas come up. Teams or individuals can assume the tasks, or the managers will assign them. Kanban maintains the original company structure, involves stakeholders more, and gives every employee a platform to voice their ideas.
In contrast, the waterfall methodology is less adaptable to frequent modifications than Kanban, which are better equipped to handle changes in schedule or scope.
| Waterfall | Kanban | |
| Implementation | Linear | Continual improvement |
| Detailed plan timeframe | Whole project | Task-by-task basis |
| Stakeholder engagement | Mostly upfront | Throughout the entire project |
| Team structure | Traditional hierarchy | Traditional hierarchy |
| Main benefit | Consistent, reliable, and controlled outcomes | Focus on vital tasks to deliver main project benefits |
Scrum
Scrum is another Agile framework that emphasizes flexibility and adaptability. Scrum aims to deliver a high-quality product in increments or “sprints” of two to four weeks, with each sprint building on the previous one. It’s iterative and incremental, emphasizing continuous improvement.
Scrum teams possess all the skills required to finish a project and are self-organizing and cross-functional. And each sprint has specific objectives, which the team collaboratively works towards. Furthermore, effective communication and collaboration between team members and stakeholders constitute the foundation of Scrum, with transparency and inspection ensuring quality.
Unlike the Waterfall model, Scrum recognizes that changes will occur throughout the project and embraces them.
| Waterfall | Scrum | |
| Implementation | Linear | Iterative |
| Detailed plan timeframe | Whole project | Typically 2-4 weeks per sprint |
| Stakeholder engagement | Mostly upfront | Throughout the entire project |
| Team structure | Traditional hierarchy | Self-organizing and cross-functional |
| Main benefit | Consistent, reliable, and controlled outcomes | Adaptable to changing requirements and customer needs |
Phases of the Waterfall Model
Each phase of the waterfall model follows a strict linear order, where a phase can’t begin until the previous one is complete. Following is a description of the phases.
Stage 1: Requirements
The first phase involves collecting all customer requirements at the start of the project, enabling subsequent phases to be planned without additional customer input until the product is finished. The assumption is that all requirements are gathered during this phase.
Stage 2: Design
During the design phase, it’s recommended to divide it into two subphases: logical design and physical design. The logical design subphase involves brainstorming and theorizing possible solutions, while the physical design subphase involves turning those theoretical ideas and schemas into specific specifications.
Stage 3: Implementation
During this phase, programmers use the requirements and specifications from earlier phases to create the functional code. Returning to the design phase may be necessary if significant changes are needed.
Stage 4: Verification
During this phase, the customer reviews the product to verify that it fulfills the initial requirements outlined at the start of the project. The final step is to deliver the finished product to the customer.
Stage 5: Maintenance
In the maintenance phase, the customer uses the product and detects issues such as bugs, insufficient features, and errors during production. Then the production team makes corrections as needed to ensure customer satisfaction.
Variation of the Waterfall Method: V-Model
Over time, the waterfall method has evolved to meet the changing needs of users, enhancing and expanding upon the original technique.
The V-Model is a widely used development model for application testing. It involves dividing the model into sub-phases and implementing corresponding testing phases for each development phase. It is also known as the Verification and Validation Model.
The model follows a sequential approach, with each phase starting only after completing the previous one. The V-Model requires detailed specifications at the beginning and involves significant customer involvement. However, it is also considered an expensive approach.
Software and Tools for Managing Waterfall Projects
Gantt charts are often used for waterfall project management. They facilitate the visualization of sequential phases, allowing project managers to assign dependencies and subtasks to each process phase. They also provide a clear view of timelines and deadlines for each phase.
However, if you’re looking for project management software to help complete your tasks. Here are some essential features you should consider.
- Ability to collaborate with your team
- Capability to take notes
- Analyze and visualize data to gain insights
- Organize projects into workflows
- Secure storage of all project data
FAQs About Waterfall Methodology
While the Waterfall model can be effective for small projects with well-defined requirements, it isn’t ideal for large projects due to its inflexibility, lack of feedback, and dependence on upfront planning and design. Moreover, it is difficult to identify the challenges and risks in the earlier stages.
Waterfall and Agile are two distinct project management methodologies. The primary difference is that Waterfall necessitates finishing each phase before moving on to the next, whereas Agile entails the team working on various project phases simultaneously. Both have pros and cons and are most suitable for different projects.
The waterfall process prohibits modifications once initiated, requiring a return to the first stage for implementing changes. However, during the design stage, alterations can be made to the design without any impact on coding or physical work.
The requirements phase is a critical step in the waterfall method, as each task depends on the previous steps. It necessitates significant planning to ensure the project’s success, with much of the project timeline dedicated to this process.
Rob Paredes
