Waterfall vs. Agile: how to choose the right approach

By Yelena Lavrentyeva, Emerging Tech Analyst, & Ed Pufal, Head of PMO Published on September 4, 2020

At the start of any software development project, we face one big question: Which software development methodology should we follow in product discovery 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 between Waterfall and Agile depends entirely on your project and requirements.

Why Waterfall model

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

Phase	Deliverables
Requirements specification	Requirements are gathered and documented
Design	Design specifications are created
Implementation	The system is developed according to the documented requirements and design document
Internal User Acceptance Testing (IUAT)	● Quality assurance by the vendor ● Detected issues are fixed
User Acceptance Testing (UAT)	● Testing by the client ● Detected issues are fixed
Deployment	● The deliverables are submitted to the client ● Technical support during the warranty period

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 software development 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

Characteristics	Waterfall / Fixed Price	Agile / T&M
Quick start	-	+
Quick time to market	-	+
Predictable budget	+	-
Flexible scope	-	+
Set timelines	+	-
Project by size	Small and mid-sized (PoC, MVP)	Mid and large-sized
Project by duration	1-5 months	Long-term projects
Payment model	The total price is fixed upfront	The client pays for an iteration or a deliverable
Client involvement	Minimal	Regular

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

Contact us

At the end of the day, it’s not about Agile vs. Waterfall. It’s all about creating software that adds value to your business and delights users

Offices:
Aliso Viejo, CA
Warsaw, PL

hello@itrexgroup.com +1 559 550 4575