A user defines a job flow of desired service cooperation according to a GUI screen displayed on a client terminal where parallel processing of plural parallel-executable jobs can be set. According to the thus-defined job flow, an instruction data generation server generates instruction data defining the content of processes, a storage location of a document as a subject, and other items. When the user selects desired one of the instruction data, the selected instruction data is sent to a cooperative processing server. The cooperative processing server interprets the instruction data and makes a service processing apparatus execute plural processes in cooperation by sending the respective service processing apparatuses processing requests that are formed so that a document will be processed according to the content of processes and processing order that are described in the instruction data