Waterfall vs. Agile: how to choose the right approach

At the start of any software development project, we face one big question: Which software development methodology should we follow to maximize productivity and stay on track? Answering this question means choosing the way we will organize the entire software development process, from planning to delivery. Project management methodologies mainly boil down to two, Waterfall and Agile:

• Waterfall methodology is a traditional development approach where the process is divided into sequential stages cascading from one to another in a waterfall manner and each stage involves new specialists, e.g., analysts, designers, developers or QAs.
• Agile methodology is a newer development approach that advocates adaptive planning, evolutionary development, early delivery, and continuous improvement, supporting flexible changes.

Both are good. The choice depends entirely on your project and requirements.

Why Waterfall model

This plan-all-the-way approach is commonly used for fixed-price development projects across various technical domains. In this model, the project consists of discrete phases where no phase begins until the prior phase is completed:

Advantages of Waterfall methodology

• High visibility: Well-documented phases and deliverables allow the client to easily track the progress and expect predictable results within the fixed budget, timeline and scope.
• No need for regular client involvement: After initial scoping is completed, no customer presence is required for other than reviews, approvals and status updates.
• Easy to control: Due to the clarity of all phases, the project is easy to handle.

Disadvantages of the Waterfall model

• Lack of flexibility: As the price and scope is fixed, making changes at the development stage can be very costly and painful, or even impossible.
• High risks: Working software is produced late in the project lifecycle, so testing is delayed. If things go wrong, the entire project can be severely impacted.
• Client exclusion: The client has no opportunity to get acquainted with the system in advance to give an opinion or clarify their requirements.
• Not suitable for complex projects: Specifying detailed and comprehensive assumptions and requirements upfront can be a significant challenge with big, complex projects.

Why Agile model

The Agile approach is based on iterative work sequences, allowing the team and the client to adjust requirements as they evolve and make incremental improvements. This approach provides flexibility to respond to the rapidly changing market environment and build a relevant product. In the Agile model, the project life cycle consists of two iterative streams running in parallel so that the process is continuous and resources are used efficiently:

Planning: analysis and requirements scoping/adjustment

Development: design, implementation, testing and releases

Advantages of Agile methodology

• Fast kickoff and simplicity: There is less planning and scoping work upfront.
• Flexibility: You can change anything at any step as the development cycle is repeated many times until the product is finished.
• Client involvement: The client sees results early and provides feedback. The client gains a strong sense of ownership by collaborating closely with the project team.
• Any stage is testable: Testing can be made at any stage, incrementally, as each deliverable is completed.

Disadvantages of the Agile model

• Uncertainty: The adhoc nature of this approach makes it difficult to fix specifics such as deadlines, costs and resources while the project may run off track due to flexibility.
• Top skills needed: The team needs highly and cross-skilled programmers and other experts for the Agile framework to be successful.

Waterfall vs. Agile Decision Matrix

Agile vs Waterfall: so, which methodology is better for your project?

Originally published at https://itrexgroup.com on September 4, 2020.