An interoperable workflow management system controls an information disclosing range of a workflow case to prevent transmission delay even when the communication path has a small transmission capacity such that cancellation of the case is guaranteed and the status of processing of the case in its destination can be immediately known. To implement the system, workflow irrelevant data or pointer information indicating the data is selectively transmitted to the destination in accordance with the workflow management system thereof. At cancellation of the case, the irrelevant data is replaced with canceling data. When a request including pointer information for the workflow irrelevant data is received from the destination system, it is assumed that the workflow case is in process.