The Waterfall Model is a traditional project management approach often used in software development. This methodology is linear and sequential, meaning that each phase must be completed before the next one begins. The model is generally divided into discrete stages: requirements gathering, system design, implementation, testing, deployment, and maintenance. Each of these stages is distinct and has its own set of activities and deliverables. The Waterfall Model is known for its simplicity and ease of understanding but is often criticised for its lack of flexibility, as it doesn't easily accommodate changes once the project has started.
Origin of the Waterfall Model
The Waterfall Model is often attributed to Dr. Winston W. Royce, although he never actually used the term "waterfall" in his seminal 1970 paper, "Managing the Development of Large Software Systems." Interestingly, Royce's paper highlighted some of the limitations and risks of a purely sequential process, which he illustrated with a model that resembled what we today call the Waterfall Model. He actually recommended feedback loops between stages as a way to mitigate the risks, but his recommendations were often overlooked. As a result, the simplified version of his model, without the recommended feedback loops, became widely known as the Waterfall Model.