To prepare a station yard switching plan accurately and efficiently for a station where trains are switched in the station yard.

An information processor receives main line data (train schedule, train service) stored in a central transportation plan management system, the data including a basic plan for a train schedule change and daily changing plans. The processor manages base data including facility conditions for individual stations, and displays the main line data in the form of schedule lines on a graphic display. Based on the displayed information, station yard train data and station yard train schedule data are put into the processor through mouse manipulation or the like, and the processor generates station yard switching plan data, using input data, and stores the generated switching plan data.