To unitarily manage schedule of an event and correspondence results on a user side to perform accurate sharing of information related to the event between related persons.

This operation monitoring system comprises: a notification timing processing part 116 determining a notification day about each the event according to prescribed algorithm, and storing it in a notification timing database 129; a schedule monitoring processing part 110 monitoring arrival of the notification day; a weighting processing part 113 performing weighting in each user system according to an importance level of the user system, a past occurring accident frequency or the like, and selecting a range of a notification target person of occurrence notice notification according to magnitude of the weighting; a notification message production processing part 114 producing a message of the occurrence notice notification in each time of arrival of the notification day; a retrieval extraction processing part 117 attaching accident information related to the user system to the message of the occurrence notice notification; and a notification processing part 111 notifying a responsible person's terminal 200 corresponding to the notification target person about the message of the occurrence notice notification.