A Systematic Review and Unified Framework for Predictive Maintenance in the Railway Domain

Predictive maintenance has emerged as a key strategic approach across numerous industrial sectors, particularly in the current context marked by the systematic integration of artificial intel-ligence (AI) technologies into asset management processes. Within the railway domain, maintenance plays a critical role in ensuring both operational reliability and safety, with maintenance-related activities accounting for up to 40% of the overall budget allocated across the V-cycle of rolling stock development. Given the essential contribution of rail transport to sus-tainable mobility and to the movement of goods and passengers, the demand for intelligent and efficient maintenance strategies continues to grow. However, a comprehensive predictive maintenance framework tailored to the railway sector remains lacking. This study presents an in-depth review of the principal methods employed in recent years, combining a PRISMA-guided systematic search of three major scientific databases Scopus, Web of Science, and ScienceDirect. A total of 61 full-text articles were retained and analyzed in detail. The paper synthesizes current research trends, frameworks, and algorithms, categorized into data-driven, model-based, and hybrid approaches, and examines their distribution across railway subsystems, revealing a con-centration of research effort on rolling-stock components such as wheelsets and switch machines relative to less-instrumented, comparably safety-critical assets such as traction, signaling, and door systems. Building on these insights, a conceptual hybrid predictive maintenance framework is proposed as a synthesis of the reviewed approaches. Finally, the paper discusses the key challenges identified in the literature and outlines open research questions with potential direc-tions for future work.