Maintenance has evolved from a purely technical function into a strategic pillar of operational continuity, production stability, and organizational safety. As industrial systems grow more complex and face increasing unforeseen disruptions, classical approaches such as reliability-centered and risk-based maintenance are no longer sufficient for managing crisis-prone conditions. In this context, Resilience-Based Maintenance (REBM) has emerged as a complementary approach emphasizing a system's capacity to absorb disruptions, adapt to changing conditions, recover functionality, and learn from experience. Drawing upon resilience engineering literature, relevant international standards, and established conceptual models, this paper proposes a five-stage framework for assessing and enhancing maintenance resilience. The framework comprises: "Preparedness and Prevention," "Monitoring, Early Warning, and Anticipation," "Response and Countermeasures," "Absorption, Adaptation, and Recovery," and "Learning, Transformation, and Continuous Improvement"—flowing logically from pre-disruption through post-recovery phases. With 194 assessment questions and a five-level maturity scale, the framework enables objective, quantitative measurement of maintenance resilience. Validation was conducted through a case study in a petrochemical complex, employing interviews with managers and technical experts alongside document review. Results positioned the organization at the "development" maturity level, scoring 2.04 out of 4. The strongest stage was "Response and Countermeasures" (2.4); the weakest were "Learning and Transformation" (1.8) and "Monitoring and Anticipation" (1.9). This research demonstrates that the proposed framework possesses high practical applicability across other national industries and provides a foundation for improving maintenance in the face of industrial disruptions.