Interactive system with explanation function for real‐time railway crew rescheduling

Abstract

To win a user's trust while railway crew rescheduling by interactively explaining the reason(s) for the solution calculated by a computer, we propose a schema for describing crew rescheduling patterns in an 'if-then-because' format, an improved method for controlling user interaction based on the patterns, and a cognitive model of the user in a state-transition form. An improved system developed using the proposed method generates crew schedules automatically by using a rule base comprising 30 patterns. Characteristic of the improved system is the use of 'because' information for explaining the computing process. System tests with an actual schedule for crews and trains in a railway line demonstrate that interactive processing with the help of an explanation function better visualizes the computing process. We evaluate our improved system by think-aloud testing. Protocol analysis of verbal comments revealed that the user state was transited in accordance with our design intent that the user state for interpreting 'because' information plays a hub role in the decision making: users spent 28% of their time interpreting 'because' information. Questionnaire survey results show that contribution of the explanation is 34%. Interactive rescheduling with the help of an explanation function is practical for real-time railway crew rescheduling.