Which is a disadvantage of the Waterfall Model?

The Waterfall Model is a linear and sequential approach to software development that consists of distinct phases such as requirements analysis, design, implementation, testing, deployment, and maintenance. One of the significant disadvantages of this model is its difficulty in accommodating changes once a phase has been completed. This rigidity comes from the fact that each phase relies heavily on the completion of the previous one, and if changes to requirements or design are needed, they typically require revisiting and revising earlier phases, which can be time-consuming and costly.

This aspect often leads to issues when stakeholders realize that their needs or the project context have evolved after the initial requirements have been established. In software engineering, where user needs can frequently change, this can result in a final product that does not fully meet current expectations, thereby limiting the effectiveness of the Waterfall Model in certain contexts.

In contrast, other models and approaches, such as Agile, are designed specifically to be adaptable to changing requirements, allowing for continuous feedback and iterative development, which the Waterfall Model does not facilitate. Thus, the difficulty in accommodating changes is a prominent limitation of the Waterfall Model and is why it is viewed unfavorably in environments characterized by rapid change.