This task of designing parts and specifying interactions among the features can be tedious and the system can be improved in that regard. Also the methodology does not appear to be suitable in cases where the interaction among features are very high or the design might have multiple interpretation. Their interactive expert system encodes rules for different molding materials and supports the synthesis of supplementary features to be put on to the initial design. The system aides the designer when performing tasks such as rib requirement, rib cross-section, rib frequency and in design of bosses. Both function and manufacturability are considered when providing help for these decisions.
Interactive feedback is provided to the designer in two forms.
First is the probability of having different forms of manufacturing defects, such as sink marks, warpage, or ejection difficulty. The second type of feedback is in the form of a warning message which suggests possible problems for the designer to avoid. The feedback is quantitative, in the sense that it gives probability of occurrence of common manufacturing defects. However this information is hard coded in the rules and the numbers that are calculated can only reflect the cases considered by the system. For example, Lazaro et al.