“The Chinese urban rail transit industry has entered a new stage of high-quality operation, and the market size of urban rail maintenance and repair has significantly expanded. The industry has an urgent demand for intelligent operation and maintenance, in order to reduce the main line failure rate, reduce manpower and increase efficiency, lower costs and extend service life. Based on this, experts have sorted out and formed a 4A architecture, formulated simplified and standardized standards, built a unified intelligent operation and maintenance platform for CRRC, created a unique operation and maintenance model, helped urban rail operation enterprises improve operation and maintenance efficiency, and provided reference for improving the quality, efficiency, and cost reduction of vehicle operation and maintenance.”