Tolerances are fundamental to manufacturing. Choice of design tolerances affects the products suitability for construction. Selection of manufacturing processes and sequence of processes affects tolerance stacking. Tolerance stacking has an effect on product quality. Unexamined tolerance stacking leads to scrap and rework thereby increasing product costs. Computer-aided tolerance analysis (cata) is presented in this paper. It is based on the "tolerance chart" technique. Cata is interactive and uses computer graphics for information display.