Which technique is regarded as a complete methodology with a four-phase life cycle?

The rapid application development (RAD) methodology is recognized as a complete approach characterized by its four-phase life cycle. These phases typically include requirements planning, user design, construction, and cutover. This structured framework allows for a high degree of user involvement and adaptability throughout the development process, which is essential in generating prototypes quickly and refining them based on user feedback.

In RAD, the focus is on rapid prototyping and iterations, which facilitates the delivery of a product that aligns closely with user needs and expectations. The methodology emphasizes minimizing planning and maximizing active user involvement, leading to faster development cycles compared to traditional approaches.

In contrast, the waterfall model is linear and may not address subsequent user feedback effectively, while agile development promotes iterative processes but doesn’t adhere to a strict four-phase life cycle. The spiral model incorporates iterative approaches and risk management but is more complex and doesn't fit neatly into a simple four-phase classification. Thus, RAD stands out as the comprehensive methodology that encapsulates the four-phase life cycle effectively.