Analyzing the effect of alternative goals and model attributes on CAD model creation and alteration

Abstract

CAD systems are proven tools which help reduce product development cycle times and improve product quality. To enhance the performance of CAD systems, engineers must be able to create CAD models of conceptual designs quickly; CAD models must also be easy to alter, so as to accommodate the rapid changes that the design undergoes through the lifecycle. In this work 3D CAD models created and altered by 30 practicing product development engineers are analyzed. The participants are experienced users of Pro|Engineer with an average of 5 years experience. The effects of modeling goals on CAD model attributes during creation are investigated; the effects of CAD model attributes on the alterability of the models are also analyzed. The results indicate that relatively simple features increase original model creation time, but increase feature reuse during alteration. Simpler features, the use of reference geometry, and the correct feature sequence improve the perception of the model during alteration by others. The retention and alteration of features (as opposed to deletion or new feature creation) is also shown to be positively correlated with model perception ratings.