1. A design assistance method for creating swing joint layout objects for interconnection among layout objects for use in a computer assisted design apparatus, the apparatus including an input means, a display device, a storage and a processor connected to the input means, the display including image data representative of layout objects and the storage including layout object data and layout object image data, comprising the steps of: (a) retrieving layout object data of layout objects specified by the input means and image data graphically representing the specified pipe layout objects from the storage; (b) collecting layout object data of the layout objects and the specified layout objects; (c) retrieving design reference data which establishes a maximum jog-over distance; (d) finding a first end of a source pipe layout object wherein the first end is not terminating in a layout object using the layout object data and the specified layout object data; (e) finding a target pipe layout object end having a least distance within the maximum jog-over distance relative to the first end using the specified layout object data and the maximum jog-over distance; (f) generating at least one swing-joint layout object interconnecting the first end and the target pipe layout object end; (g) storing layout object data representing the swing joint layout object and adding the stored layout object data to the collection; and (h) displaying image data representing the layout object data of the collection.