What is Waterfall Lifecycle

The Waterfall lifecycle or the waterfall model is a traditional approach to software development where each phase of the project flows sequentially, like a waterfall. This means you complete one step at a time; i.e like planning or coding, before moving on to the next. It’s structured and easy to understand, making it ideal for projects with clear, fixed requirements.

This article will explore how the Waterfall model works and how it’s still relevant in 2024, even as technology and projects evolve.

Note: The term waterfall model and waterfall lifecycle will be used interchangeably in the article

What is the Waterfall Lifecycle/Model?

The Waterfall model or waterfall lifecycle is a structured, step-by-step approach to software development, where each phase is completed before progressing to the next one.

It is one of the earliest and most straightforward methodologies, focusing on structured, step-by-step processes, such as requirements gathering, design, implementation, testing, and maintenance. Once a phase is finished, the process moves downward like a waterfall without going back.

This model is commonly used for projects with clear, fixed requirements that are expected to remain stable throughout the development process.

Industries like construction, manufacturing, and certain areas of software development still rely on the Waterfall model, especially when the project scope is clear and fixed from the start.

For example, industries such as healthcare, finance, and government, have strict regulations and compliance requirements. In such cases, the Waterfall model is mostly preferred since it has a clear and structured approach.

These sectors often need a formularized process with defined targets to ensure that all aspects of a project such as documentation, testing, and quality assurance are thoroughly completed before moving on to the next phase.

Use Cases of Waterfall Lifecycle

The Waterfall lifecycle is best suited for software projects where the requirements are clear, fixed, and unlikely to change during development. It is effective when a clear, step-by-step approach is required. Some common use cases include:

• Custom Software for Well-Defined Industries: Utilized in industries such as finance or healthcare, where regulations are strict and documentation is key.
• Embedded Systems: Used for embedded systems like those used in automotive or aerospace, where the requirements are stable and changes are minimal.
• Legacy Systems Maintenance: Leveraged when updating or maintaining existing software with known requirements and predictable outcomes.
• Shorter, Low-Risk Projects: Utilized in projects where the scope and objectives are clear from the very start and the likelihood to evolve is low.

In these situations, Waterfall provides a clear, linear path to completion, making it easier to manage timelines and deliverables.

Importance of the Waterfall Lifecycle

Here are reasons why the waterfall model is important:

• Clear Phases: The waterfall model has clear, well-defined phases like requirements, design, coding, and testing that help to keep things organized.
• Good Documentation: Waterfall emphasizes creating detailed documentation at every stage, which reduces confusion and miscommunication.
• Predictable Timelines: The linear approach helps set realistic deadlines and manage project timelines more effectively.
• Minimal Changes: It works well for projects where the requirements are unlikely to change, so there’s less need for backtracking or adjustments.

Example: Consider developing a software system for a bank where the requirements for security and compliance are clearly documented from the beginning. These requirements are fixed and are less likely to evolve. The waterfall model, with its clear and structured process, ensures that each stage concludes on time while meeting important standards.

In short, the Waterfall model works well for software projects with clear and fixed goals. Its well-defined approach ensures that everything stays on track and helps deliver the project on time.

6 Phases of Waterfall Model in Software Engineering

The working of Waterfall model follows a clear, linear path that mainly covers six key phases. Each phase is completed before moving to the next for seamless tracking and management.

Here are the 6 main phases of the waterfall model:

1. Requirement Gathering and Analysis

This is the first phase where all project requirements are gathered from the client or stakeholders. The objective is to correctly define the software’s features, functions, and user needs. A solid foundation is created by this phase for the entire project.

Example: Imagine a company that wants to build an inventory management system. In this phase, they clearly define all the features the software must have, like tracking stock levels, generating reports, and handling orders. The development team documents all these requirements in detail to guide the rest of the project.

2. System Design

Here, the software architecture and design are planned according to requirements. Designers create detailed models, user interfaces, and system structures, laying out how the software will work technically.

Example: For the inventory management system, the design phase would involve creating mockups for the user interface, designing how the database will store inventory data, and deciding on the system architecture, including the technologies to be used for both the front-end and back-end, as well as establishing security protocols and scalability requirements.

3. Implementation (Coding)

In this phase, the developers start with writing the actual code. They leverage the designs and specifications from the previous phase to build the software system and align it with the defined requirements.

Example: The development team now starts coding the inventory management system. They write the code to handle stock entries, orders, and generate reports to make sure that each feature works as intended as per the design documents.

4. Integration and Testing

After coding, the software is integrated, and testing is conducted to detect bugs and issues. This ensures that the software works correctly and meets the original requirements. This phase includes unit testing, system testing, and acceptance testing.

Example: After the inventory system is coded, the team runs tests to ensure everything works correctly. They verify if the system accurately tracks stock levels, if the reports match the expected formats, if the user interface is intuitive and error-free, etc.

5. Deployment

Once testing is complete and the software is fully functional, it’s deployed to the production environment. This is when the software is made available for end users.

Example: After the inventory management system is fully tested, it is installed at the company’s offices, and staff start using it to manage inventory and track orders. The software will now be live and functioning.

6. Maintenance

After deployment, the software is in the maintenance phase. It involves fixing bugs, making updates, and adding new features as needed. This phase makes sure that the software remains functional and up-to-date.

Example: A few months after deployment, the company requests a new feature; for example, a notification system for low stock levels. The development team goes back to make this change and releases an updated version of the system. The software may also need updates for compatibility with new operating systems or hardware.

Features of the SDLC Waterfall Model

The SDLC Waterfall model is like a well-organized blueprint for building software. It’s straightforward, and easy to follow, and is perfect for projects with fixed requirements and a clear vision.

Here are the features that make the Waterfall model tick all the boxes:

• Step-by-Step Progression: Like climbing stairs, each phase must be completed before moving to the next. No skipping steps, no shortcuts, just steady, sequential progress from start to finish.
• Clear, Defined Phases: The Waterfall model breaks the project into clear, manageable phases like Requirements, Design, Implementation, Testing, Deployment, and Maintenance. Each phase has a distinct goal, keeping the team focused and on track.
• Predictable Milestones: Since each phase has defined objectives, it’s easier to set clear milestones and deadlines, making project timelines more predictable and easier to manage.
• Minimal Changes During Development: Waterfall reduces the need for constant revisions since requirements are clear, upfront , and unlikely to change during the process. This lets the team stay focused on their original objectives.
• Heavy Documentation: Each phase requires detailed documentation, which helps ensure transparency and clarity throughout the development process. This documentation can also be helpful for future maintenance or upgrades.
• Easy to Manage for Small to Medium Projects: The linear, straightforward approach makes Waterfall well-suited for small to medium-sized projects where the scope and requirements are clear from the beginning. It’s especially useful in environments that need strict regulation or compliance, like healthcare or finance.
• Clear Roles and Responsibilities: Since each phase is distinct, it’s easy to assign specific tasks to different teams or individuals, with clear roles and responsibilities for each part of the project.
• Focused Testing Phase: Software testing comes after the development phase is complete, allowing the team to focus purely on fixing issues without distractions. This is ideal for projects where the software’s behavior is well-understood and unlikely to change.
• Good Communication: Since everyone knows what phase is happening and what’s expected, communication is smooth and transparent. Stakeholders are always in the loop, and therefore tracking progress is easier.
• Less Scope Creep: With all requirements clearly defined upfront, the chances of the project’s scope expanding unexpectedly are minimal.

Waterfall vs Agile Method: A Quick Comparison

Waterfall and Agile Models are two of the popular SDLC models.

Here’s a simple and easy-to-read table that highlights the differences between the Waterfall and Agile methodologies.

Think of Waterfall as a strict, step-by-step guide, while Agile is more like an adaptable roadmap, always ready for detours.

In summary, Waterfall is structured and rigid, while Agile is flexible, adaptive, and focuses on iterative delivery with ongoing collaboration.

Advantages of the Waterfall Model

The Waterfall model has some clear advantages, especially when you know exactly what you’re building and need a predictable, structured approach.

• Clear Structure: Each phase of the waterfall model is clearly defined. Therefore, you knows what comes next. This makes project planning, management, and execution straightforward.
• Easy to Manage: Since the process is linear, tracking progress is easier. You know exactly where the project stands at any given time, making it easy to report milestones and deadlines.
• Well-Defined Requirements: Waterfall works best when you have fixed, unchanging requirements. You can spend time upfront to fully understand the project, minimizing ambiguity later on.
• Predictable Timelines and Budgets: Since the phases are well laid out, you can set realistic timelines and budgets. This makes the Waterfall model great for projects with strict deadlines or regulatory requirements.
• Thorough Documentation: Every phase is documented to ensure that there’s a clear record of decisions, designs, and requirements.
• No Surprises: Since everything is planned in advance, the likelihood of unexpected changes or “scope creep” is low. This means fewer last-minute changes and less worry about shifting priorities.
• Easy to Understand: Its simplicity and linear progression make it easy for teams, especially non-technical stakeholders, to understand the entire process and track progress.

Disadvantages of the Waterfall Model

Despite its structured approach, the Waterfall model does come with certain limitations, particularly in projects that require flexibility or constant feedback:

• Inflexibility: Once a phase is completed, you can’t go back and make changes easily. If requirements change or new information emerges, making adjustments is difficult and costly.
• Late Testing: Testing only happens after the development phase, meaning bugs and issues are only discovered toward the end. This can lead to major fixes late in the project, which can delay delivery.

• Longer Time to Market: Since you only deliver at the end of the project, it takes longer to get the product into the hands of users or stakeholders. Agile, on the other hand, delivers incremental updates that can be tested and used sooner.
• Not Ideal for Uncertain Projects: If you’re working on a project with unclear or changing requirements (like a new product or evolving app features), Waterfall can become a problem. It’s hard to adapt once you’re deep into the process.
• High Risk and Uncertainty: Since the waterfall model stresses completing everything before launching increases the risk of missing the mark. If the initial requirements are misunderstood, it may only be clear in the final stages.
• Limited Customer Feedback: The customer or end-user isn’t typically involved until the testing phase, meaning there are fewer opportunities for input or adjustments based on their feedback throughout development.
• Overload of Documentation: While documentation is useful, the Waterfall model’s emphasis on detailed documents at each stage can slow down progress and make the process feel heavy and bureaucratic.

Test Automation in Waterfall Model using BrowserStack

In the Waterfall model, testing usually takes place after development is complete. By the time you start testing, everything is built and ready for evaluation.

However, testing can be time-consuming and expensive, especially when you need to ensure the software works across different browsers and devices.

This is where BrowserStack comes in. It helps automate cross-browser testing on real devices and browsers without needing to set up a complex testing environment.

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By integrating BrowserStack into your Waterfall process, you can:

• Test Across Multiple Browsers: Quickly ensure your software works on browsers like Chrome, Firefox, Safari, Edge, and the like with cross browser testing.
• Cloud Infrastructure: BrowserStack is a cloud-based platform that doesn’t require you to set up or maintain browsers or physical devices locally.
• Real-device testing: BrowserStack provdies a vast real-device cloud, allowing you to run tests on 3500+ real device, browser, and OS combinations, thus enabling you to test under real user conditions.
• Scalability: BrowserStack supports real-device and parallel testing on a cloud-based infrastructure and lets you run hundreds of tests across different environments.
• Save Time: Automated tests run faster, helping you find and fix bugs sooner in the testing phase.
• Improve Quality: With BrowserStack, you can run thorough tests on various platforms to catch issues that might be missed in manual testing.

Using BrowserStack for test automation in the Waterfall model makes the testing phase faster and more effective, so your software is ready for deployment without delays.

Conclusion

Waterfall is like a straight road with no turns, great for projects where you know the destination and the path is clear and Agile is more like a winding path with plenty of detours perfect when you’re exploring new territory and need the flexibility to adapt along the way.

However, the Waterfall model isn’t as flexible if requirements change during development. Having said that, it is ideal for projects with well-defined needs or regulatory requirements, and can deliver high-quality results. And with tools like BrowserStack, you can streamline testing and ensure a smooth deployment process.

In short, Waterfall works best when you need a methodical, predictable approach. With the right tools and processes, it’s still a great choice for certain software projects in 2024, especially those with clear goals and defined timelines.

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