To enable operators for executable processes to carry out the processing of these processes if there is a margin for the working load of these operators without sticking to the sequences of the standard processes in the stripping work during prepressing.

If the stripping work during prepressing is assumed to consist of three processes; for example, A, B, C, the server means A1 of the process A, the server means B1 of the process B and 'the server means C1 of the process C are connected by a network means N and the combination of the process management information and imperfect digital plate making data is periodically and automatically cycled between the server means arranged in the process which requires the processing and is incomplete without sticking to the sequences A, B, C of the standard processes. The operators of the respective processes occasionally carry out the processing in their own processes relating to the incomplete digital plate making data combined as a set with the process management information described above and simultaneously rewrite the progression condition of their respective own processes in the process management information.