Abstract: An automatic parts placement system is provided which is capable of placing parts in proper positions, in a short time, on a printed wiring board to realize the shortest total wiring length. Parts are each added to a parts group which is generated based on a position designated part and parts specific gravity of the part is determined. The heavier parts specific gravity of part is placed in the closer position relative to the position designated part, by applying actual specific gravity in physical phenomenon.

Abstract: A layout data converter (111) is supplied with layout data and prepares segment data. In response to an instruction from an operating section (102), an instruction input device prepares necessary data. In order to move each component in a movement target direction, a terminal constraint graph generator (104) calculates, with reference to the respective data, a moving group relative movement limit length within which one component is movable towards another component with a wire interposed therebetween, subtracts the moving group relative movement limit length from a moving distance of the one component to obtain a difference, and memorizes the difference as a moving distance of the other component. A component compactor (107) moves each component over the moving distance thus obtained. A wire compactor (108) calculates routing limit position data representative of a routing limit position determined by pulling the wire between the components around the other component.