Article provides a good overview of data needed to manage a product's dimensions over the life cycle. The comments about datum identification and multiple references in numerous drawings is dead on accurate; this has been the root of many headaches. The focus on UGS systems only limits the usefulness of the article and can give the impression of an extended advertisement. It would be of interest to know of other packages that can do the same or similar things. Some of the grammar should be cleaned up to make it more readable. There are several instances of the wrong word being used (e.g., 'to' instead of 'too') which requires rereading the sentance (sometimes several times) to understand the thought being conveyed. On the balance, a useful article. Some additional work would make it more readable (and useful).