In a system that sends and receives one or more data files and a statistics information file that holds information of the total number of those data files, event processing is not carried out each time a file arrives. Instead, event processing is carried out on all of the files in response to an event of the statistics information file arriving, which reduces the number of times event processing is executed. The amount of time that has elapsed in the event processing is monitored, and the processing is continued by executing different event processing before a timeout occurs.