Abstract: A line system has control units each of which is connected to a processing device (a device for processing a workpiece, for example), and which are connected through a network. The system has a memory which stores data for use in processing the workpiece and which is provided for each control unit, and maintains the contents of the memories provided for the respective control units identical to each other.

Abstract: The present invention relates to a parts mounting sequence determination method which determines mounting sequence of m parts so that each of the total m parts is sequentially mounted on a board by a turret table mounter, comprising steps of:(a) obtaining and storing tact time, for all the parts of the m parts, for sequentially mounting two optionally selected parts among the m parts in advance;(b) calculating the minimum tact time of all tact times on all routes including a coming step n which is consecutively processed from a step i, to each part of optional m.sub.i (m.sub.i <m) parts of the m parts which are capable of being allotted in step i;(c) allotting the first part in a series of parts which provide the minimum tact time in the m.sub.i tact times in step i calculated in step (b); and(d) repeating the steps (a) through (c) for each part after step (i+1).