PURPOSE: To perform a scheduling operation with good balance among the busy states of tasks as the entire group by providing a means which estimates the busy state of task based on the input schedule information and a means which controls the public possibility of the individual schedule information to other persons.

CONSTITUTION: A communication means 10 performs the communication between the schedule management systems, and a communication instruction interpretation means 20 interprets the instructions which are communicated between both schedule management systems. A task request means 30 selects a proper group member and requests it to carry out a task. A public information decision means 40 automatically decides the possibility of opening schedules to public to other members. A publication grant input means 50 makes a user designate the possibility of opening schedules to public of other members for every task. A group management means 60 manages the group members and the relationship defined among the tasks shared by plural members. A task load management means 70 estimates the busy state of task, and a schedule management means 80 stores and manages the individual schedules.