In contemporary society, marked by rapid technological progress, cultural diversity, and various environmental and political issues, organizations must continuously adapt and strategize to remain competitive and meet societal demands. In this context, public and private organizations must develop projects and adopt project management methodologies to navigate complex changes effectively. Thus, project managers and other professionals involved in project activities must continually adjust their strategies to align with prevailing circumstances. This chapter examines the integration challenges of agile and predictive methodologies with established project management standards, ISO 21500 series. It emphasizes the importance of monitoring project progress and quality beyond traditional documentation, advocating for using Agile project management tools to enhance speed, efficiency, and overall quality. Furthermore, it explores the convergence of the ISO 21500 series, Agile Project Management, and the difficulties encountered in implementing these standards alongside agile approaches such as Scrum and Kanban. The chapter proposes practical solutions for implementing ISO 21500 series standards within agile frameworks.