Abstract
In manufacturing systems, it is essential to consider the functional conditions of a manufactured part. These conditions are influenced by the geometric and dimensional constraints imposed by the initial part diagram. To date, one-dimension chains of dimensions and geometric specifications have been used to ensure the manufacture of defect-free parts. This modelling technique, however, is inefficient since parts are three-dimensional. To address this problem, we have developed a three-dimensional geometric defaults modelling process using small deviation torsor (SDT) theory. This three-dimensional modelling allows for the quantification of geometric defaults in order to respect the imposed manufacturing constraints.