AbstractAmong mass transportation facilities, high-speed rail systems not only connect major cities but they also drastically shorten the transportation time. The high-speed train maintenance works are an important part of the safety operation system. Also, the reasonable planning and maintenance works execution can ensure the safe running of trains, improve the quality of operation, and reduce company costs. The regular maintenance is a critical element for providing an excellent transportation service to the public. The present study uses data envelopment analysis (DEA) and the Malmquist productivity index (MPI) to analyze the multiyear trends in productivity for the yearly and midterm maintenance efficiencies of 12 high-speed trains in Taiwan. These features are evaluated through systems thinking, and suggestions are offered towards improving those factors responsible for the inefficiency. The results show that eight of the trains studied had attained satisfactory maintenance efficiency, whereas four could be improved, yielding a productivity of 66.7%. In addition, by following the trends in the MPI values, it was found that the technical efficiency (TE) and the total factor productivity (TFP) are the main factors responsible for stalling maintenance performance, contributing a decline of 37.1% and 37.7%, respectively. Our study has identified three factors leading to maintenance inefficiency. These three factors are: (1) a change in the scope of the contract, (2) a change of work methods, and (3) a lack of effective communication between the management and the customer. It is hoped that this research can provide useful information that will allow decision-makers to avoid erroneous decisions caused by poor intuitive judgment or inadequate considerations, and to formulate correct policies, to improve maintenance productivity, and to ensure that trains can continue to run safely.