A system and a method, capable of executing a process operation by using a plurality of applications, are provided. While a corresponding relationship of data used in these applications is previously defined, a data converting unit converts data about an execution result of an application. An application initiating unit executes another application by using the converted data. The present invention has an object to provide both a system and a method, capable of controlling an execution of an application program, while data can be transferred/received among plural application programs having no specific relationship with each other. Furthermore, the present invention has another object to provide both a workflow system and a workflow method, capable of utilizing application programs which are different from each other every process previously defined in the workflow.