A notice board business system database stores therein collectively the contents of all the data heads relating to a series of business processes, and is held in common in the form of a notice board through clients by all the related persons in charge of the tasks. A status change rule sets the data head in which the data input should be completed with respect to each of the task processes. A status watcher refers to both the notice board business system database and the status change rule to make the task process change from the current task process to the next task process when the predetermined data input has been completed in the process in task so as to inform the related client of that the status change has occurred. In addition, the status watcher refers to a status change limit rule for setting the data input completion due date for each of the task processes so as to inform, when the processing due date is drawing near, the related client of that the processing due date is drawing near.