Comparative Analysis of Agile and Traditional Software Development Methodologies: A Systematic Review of Project Success, Flexibility, and Organizational Performance

Running Title: Agile vs Waterfall SDLC

Abstract

Software Development Methodologies have a very important impact on the success of the project, software quality, user satisfaction, and organisation performance. This study conducts a systematic qualitative review of the literature and industry evidence relating to Agile and traditional waterfall software development methodologies from 2010 to 2025, with particular focus on studies published in the last five years (2020–2025).The data were gathered from the databases including Scopus, IEEE Xplore, SpringerLink, ScienceDirect and Google Scholar. Both methodologies are assessed on criteria such as project success rates, adaptability, stakeholder participation, risk management, schedule and cost performance, and outcomes of software quality. The results showed that in a dynamic and a rapidly changing project environment, Agile methodologies are consistently more effective than Waterfall methodologies. Research has demonstrated that the success rate for Agile projects is about 40%, with about 10% failure rate, while Waterfall projects have a success rate of about 15% and failure rate of about 30%. Agile practices show greater adaptability, ongoing engagement of stakeholders, incremental risk management, and responsiveness and flexibility to changing needs. However, structured and predictable processes make Waterfall methodologies effective in projects that have static requirements, limited budgets, strict documentation requirements and regulatory compliance requirements. The review also reveals gaps in current research, such as limited longitudinal studies, lack of evidence to assess the outcomes of defect management and maintenance, publication bias, and self-reported metrics. The research findings suggest that there is no single best practice methodology, rather an appropriate development approach should match project complexity, organizational culture and the need for operations. For enterprise software that is large scale, the combination of Agile flexibility and Waterfall governance has been recommended and is known as hybrid frameworks.