Design process using CAD system takes two steps of making 3-dimensional model and then adding the necessary annotations such as label, dimension etc. to the projected image of the model so as to have drawing format. Dimensioning work included in the second step of the design is usually tedious, and motivated to be automatic.
Automatic dimensioning systems introduced so far are found to be applicable to the single solid object drawing but not applicable to the composite drawings such as plant or ship design drawing, on which the dimension mainly represents the distance and/or orientation of each object having no logical structure for dimensioning.
This study covers the mechanism of dimension chaining by introducing design practice and deciding dimension position with minimum interference against existing graphical components by simplified spatial decomposition.