The WSRMAcknowledgementIntervalInMs workflow system property sets the interval in milliseconds for acknowledgment of the receipt of a message between a reliable messaging source and a reliable messaging destination.
Web Services Reliable Messaging is a web services protocol that ensures the reliable exchange of messages between systems. If the reliable messaging source does not receive an acknowledgement that the message was received by the reliable messaging destination, the acknowledgement request is sent again at the specified interval until an acknowledgment is received. The default value is 200 milliseconds.