WATERFALL MODEL Meaning and
Definition
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The waterfall model is a software development process model that follows a sequential, linear approach to designing and developing software. It is called the waterfall model due to its cascading flow-like nature, where each phase of development flows into the next one without any overlap or interaction between them, similar to a waterfall cascading down from one stage to another.
In the waterfall model, the software development process is divided into a series of distinct phases, which typically include requirements gathering, system design, coding, testing, and maintenance. Each of these stages is completed one after the other, with the output of one phase serving as the input for the next phase.
This model is often characterized by its rigidity and adherence to a predetermined plan. The waterfall model assumes that all requirements and specifications are clear and well-defined from the beginning, and any changes or alterations are not expected or accommodated easily. The development progresses through the stages in a linear fashion, and once a stage is completed, there is usually no going back to make changes or modifications.
While the waterfall model offers a clear and structured approach, it may result in limitations when requirements change, as it lacks flexibility in accommodating modifications. However, it still finds utility in certain industries and projects where requirements are stable, well-known, and unlikely to undergo significant changes throughout the development process.
Etymology of WATERFALL MODEL
The term "waterfall model" in software development comes from the concept of a waterfall, which is a natural phenomenon where water flows downward in a continuous vertical descent. The model was first introduced by Dr. Winston W. Royce in a paper published in 1970, titled "Managing the Development of Large Software Systems".
The word "waterfall" is used metaphorically to describe the sequential flow of activities in the software development process, where each phase is completed and flows to the next one without the possibility of revisiting previous stages. Just like water flowing down a waterfall cannot move back up, the waterfall model suggests a one-way movement through the different phases of software development, including requirements analysis, design, coding, testing, and maintenance.
Despite its popularity, the waterfall model has faced criticism due to its rigid and inflexible nature, which often led to issues in meeting changing requirements or adapting to unforeseen circumstances.
