We model the relationships between the message formats of a business system and their semantics in a machine-processable knowledge base. We describe a message-mapping technique that extracts the relationships between the message formats of several systems semiautomatically by using the class characteristics of the semantics and stores these relationships as past system design knowledge. In addition, we propose process-mapping, which is a technique that discovers suitable software components for system cooperation. We evaluate these methods using the interface specifications of actual service management systems and show that the frequency of interface adjustment can be reduced.