A distributed processing method and system including a plurality of processors connected via a transmission path, in which a function is provided to an arbitrary processor to receive information and data passing through the transmission path and to obtain the received data based on information indicating input/output relationships between modules corresponding to the association of processing between the modules. When required, necessary portions of the obtained information and logging results are extracted, so that not only the time series data log but also the information or data log can be collected corresponding to the flow of a sequence of processing by establishing a display or print-out module. Furthermore, when data is received from an external device, the system generates a message having information indicating the order of the data and the content code representing content of the data and sends the message to the transmission path. A processor receives messages from the transmission path, and stores the data in accordance with each content code in an order which facilitates trouble shooting of the system.