Abstract
Railway scheduling is a large-scale combinatorial problem including various kinds of constraints and traffic demands. It is essentially impossible to satisfy all demands, therefore, experts must prepare practical train diagrams by compromising over some demands by trial and error methods.
This paper describes an interactive support system for train diagram preparation, DIAPLAN (Train Diagram Planning Support System). DIAPLAN is based on expert problem solving process, and prepares a train diagram on simulating running trains and planning local schedules alternately, therefore experts can easily understand solving process and make good diagrams using DIAPLAN. DIAPLAN prepares a complete diagram automatically from given initial conditions for a train under monitoring by the experts. Whenever experts want to modify the diagram, they can take the initiative in preparing, modify and re-prepare it quickly and repeatedly. Therefore, without useless trial and error, experts can prepare the fine diagram which totally satisfies most of demands.
