This standard is formulated under the jurisdiction of the National Technical Committee for Elevator Standardization of China. It is applicable to the maintenance activities of traction and positive drive lifts, hydraulic lifts, escalators and moving walks, covering the whole scenarios of preventive maintenance, corrective maintenance and emergency maintenance. Compared with the old version, the core upgrades of this revision include: first, reconstructing the maintenance classification system, dividing maintenance into four categories: preventive maintenance, fault maintenance, transformation maintenance and emergency maintenance according to the maintenance purpose and content, and clarifying the work content, process requirements and quality standards of different types of maintenance; second, refining the capacity requirements of maintenance organizations and personnel, clarifying the qualification, management system and equipment configuration requirements of maintenance units, formulating the skill level, training assessment and certificate holding specifications of maintenance personnel, requiring that maintenance personnel must pass special skill assessment before taking up their posts; third, improving the whole-process maintenance operation specifications, formulating detailed maintenance operation procedures, safety protection requirements and quality inspection standards for the core components of lifts and escalators, and clarifying the whole-process management requirements of risk assessment before maintenance, process control during maintenance and acceptance test after maintenance; fourth, adding the classification specification for preventive maintenance, dividing preventive maintenance into three grades A, B and C according to the service life, operation frequency and use scenario of the elevator, clarifying the cycle, items and technical requirements of different grades of maintenance, and promoting the transformation of elevator maintenance from "fixed cycle maintenance" to "on-demand maintenance"; fifth, strengthening the maintenance safety management requirements, formulating the safety operation procedures, on-site protection requirements and emergency disposal specifications for maintenance operations, and clarifying the special safety requirements for high-altitude operations, live operations and in-shaft operations; sixth, improving the maintenance record and traceability management requirements, clarifying the content, retention period and traceability management specifications of maintenance records, requiring maintenance units to establish a complete maintenance file to realize the traceability of the whole process of elevator maintenance. The implementation of this standard has comprehensively standardized the operation behavior of China's elevator maintenance industry, improved the elevator maintenance quality and safety management level, and also promoted the integration of China's elevator maintenance service standards with the international market, providing standardized support for the global export of China's elevator maintenance services and technical solutions.