What type of model is usually adopted in a structured approach to systems development?

The Waterfall model is a linear and sequential approach to systems development that is commonly associated with structured methodologies. This model is characterized by distinct phases such as requirements gathering, design, implementation, testing, and maintenance, where each phase must be completed before moving on to the next. This structured framework is beneficial for projects where requirements are well understood upfront and changes are minimal, as it allows for a clear plan and timeline.

The Waterfall model emphasizes thorough documentation and validation at each stage, ensuring that developers and stakeholders have a complete understanding of the system before moving on to subsequent phases. This systematic process helps in maintaining order and discipline, which is essential in environments that require rigorous project management and quality control.

In contrast, other methodologies like Agile focus on iterative processes and adaptability, while the Spiral model incorporates risk assessment and iterative development. Incremental models also allow for flexibility but typically do not follow the strict sequence that defines the Waterfall approach. Thus, the Waterfall model remains the standard choice for many traditional systems development projects within structured frameworks.