Abstract
This paper proposes a guideline on the high operability interfaces of 3-D Computer-Aided Design systems by evaluating the operability of commercial 3-D CAD systems. The evaluation is conducted by the key-stroke-level-model which is derived by counting the number of keyboarding and mouse-clicking. In this study, six 3D-CAD systems are used for analyzing the operability and usability. It is proposed that sketch operations should be improved to get the high operability and usability.
