This report provides a comprehensive overview of adaptive methodologies used in software development, contrasting them with traditional predictive approaches. It focuses on three key methodologies: Scrum, Extreme Programming (XP), and Unified Process (UP). The report delves into the core concepts of adaptive methodologies, emphasizing their iterative nature and ability to accommodate changing requirements. It details the stages, advantages, and disadvantages of each methodology, including the specific practices and roles within Scrum, the emphasis on teamwork and customer satisfaction in XP, and the phased approach of UP. The report also includes an event table, model class diagram, design class diagram, use case diagram, and use case description to illustrate practical applications. Finally, it offers a recommendation on the most suitable methodology for a specific project (FFSL system), highlighting the benefits of Scrum for continuous teamwork and client involvement. The report is a student contribution to Desklib, a platform offering AI-based study tools.