The LAGSSE Framework: Integrating Lean, Agile, and Green Principles for Sustainable Software Engineering

The demand for sustainable digital and information systems requires a transformative shift in software engineering practices that balance technical performance with economic, environmental, and social responsibility. This paper introduces LAGSSE, which is a novel framework that integrates Lean, Agile, and Green principles to advance Sustainable Software Engineering (SSE). LAGSSE operationalizes six interconnected sustainability dimensions: technical, environmental, economic, social, process, and infrastructure through a layered architecture and lifecycle‐based approach, underpinned by the OntoSuSD ontology for semantic clarity and traceability. A two‐phase validation strategy confirms the framework's strength; that is, a Delphi‐based expert study ( n = 75) establishes conceptual clarity and applicability, while simulation‐based evaluations demonstrate measurable improvements in energy efficiency (25%), defect reduction (33%), deployment speed (30%), and stakeholder satisfaction (24%) compared to baseline Agile practices. Visual models, statistical charts, and a Sustainability Performance Score (SPS) equation reinforce the framework's empirical grounding and practical utility. This framework not only addresses critical gaps in existing SSE frameworks but also provides an adaptable, comprehensive, and validated pathway for embedding sustainability into software engineering education, industry practice, and policy development.