ABSTRACT
Features have been playing an important role in representing the design and transmitting necessary data to various applications. Because of the nature of the process planning tasks, different types of features are required. Two approaches have been used, namely design by features and feature recognition. In the design by features approach, the designer defines the initial CAD model in terms of various form features which are directly relevant to the manufacture whilst by feature recognition, a computer program extracts necessary information from a CAD model and converts it into features. Design by features has been used by many researchers. This method, however, can demand extra work for the designer to tag features. Feature recognition has not reached its maturity although it seems an effective route. More detailed reviews are provided by Bronsvoort and Jansen (1993), Case and Gao (1993), Shah (1991) and Woodwark (1988).
