Smart Manufacturing for Production Flexibility in Industry 4.0–5.0: A Systematic Review, Gap Analysis, and Framework

ABSTRACT: Smart manufacturing has emerged as a key enabler of industrial digital transformation, fostering intelligent, interconnected, and adaptive production systems. At the same time, production flexibility has become a strategic imperative for managing demand volatility, supply chain disruptions, and mass customization requirements. Despite substantial advances in Industry 4.0 and the transition toward Industry 5.0, the literature remains conceptually fragmented and largely technology-driven, with limited integration of organizational, human-centric, and sustainability perspectives. This study presents a systematic literature review of smart manufacturing for production flexibility, synthesizing existing research across major enabling technologies and industrial application domains. The review identifies three critical gaps in the current body of knowledge: (i) the lack of a unified and multidimensional conceptualization of production flexibility, (ii) insufficient integration between cyber–physical infrastructures and socio-technical systems, and (iii) the limited incorporation of human-centricity and sustainability as core design principles. The findings demonstrate that production flexibility should be viewed not as a direct technological outcome, but as an emergent system-level capability arising from the dynamic interaction of digital technologies, organizational structures, and human intelligence. To address these gaps, the study proposes a seven-stage Smart Manufacturing–Production Flexibility (SM–PF) transformation framework encompassing digital connectivity, system integration, intelligent analytics, adaptive automation, autonomous systems, human–AI collaboration, and ecosystem integration. The framework conceptualizes the evolution of flexibility from conventional operational adaptability toward anticipatory, reconfigurable, cognitive, and ecosystem-level capabilities. This study contributes an integrated theoretical foundation and a structured roadmap for future research and industrial transformation in smart manufacturing.