A data distribution apparatus and method for distributing data from a first group of devices to a second group of devices through a series of controlled coupling units to evenly distribute processing load associated with the data among the second group of devices. The coupling units have memory for storing values relating to an accumulated processing load of data distributed through the coupling unit. The coupling units distribute data and/or descriptive indicators representing data based on kinds of data, such as job classes, and processing loads that are previously estimated. By distributing based on processing load, a plurality of processes can be performed nearly simultaneously without excess waiting.