Producing optimized schedules for nightly engineering works is highly complex with numerous engineering, operational, and safety rules to consider as well as priority and urgency of each of the subway engineering tasks to be performed. By using an AI rule-based approach combined with heuristic-guided search and Genetic Algorithms, our "AI Engine" ensures Hong Kong's subway system operates smoothly each and every day.
"Ensuring the safety of engineering staff and the consistently optimal operation of the MTR lines is the top priority of this AI scheduling system. With CityU's vast experience in this area, we are happy to have them working with us on this project," Ir Richard Keefe MTR Infrastructure Engineering Manager
Mass Transit Railway Corporation (MTRC), established in 1975, is one of the most heavily utilized underground railway networks in the world. Since the opening of the first line in 1979, the MTR has been providing a safe, reliable, and efficient service to passengers. The current subway is now over 88 km with 6 lines through 50 stations with a new Disneyland Resort Line opening in late 2005.
MTR carries 2.4 million passengers daily, making it one of the busiest in the world. Despite the large traffic-flow, the MTR has set for itself a very high service quality standard - train punctuality and delivery must be 99% and 99.5% on time respectively. To ensure these standards are met, the scheduling of engineering works must be optimized so that all necessary maintenance tasks are done in a timely manner.
Through the use of AI techniques, we were able to help the subway streamline their scheduling/rescheduling processes and maximize their resource utilization, while providing early identification of potential violations of safety and operational regulations and guidelines for all scheduled engineering works. In addition, valuable domain knowledge and expertise related to these regulations and guidelines are now quantified, coded and preserved within the organization, for use by this and other systems. Our AI Engine also makes use of several innovative techniques, such as a non-intrusive XML rule-engine, intelligent self-healing coding, and combining heuristic search with genetic algorithm. This is probably the first AI system to be deployed in Asia Pacific that uses these innovative techniques as well as a modern service-oriented architecture.
Our AI Engine has been in daily use since July 2004. Since then all engineering works possession requests are processed and scheduled by our AI Engine, and MTR has been able to consistently maintain its quality commitments and standards. Workflows have also been greatly streamlined; time needed for the entire decision making process has been reduced.