There are good reasons for having both Attributes and Expressions even if some capabilities look and feel redundent. Granted, much of it is the result of legacy archtecture and schemes that we need to maintain since they are important to the way some of our oldest customers are using the system. True, if we were given the opportunity to start over, we probably would do things very differently, but alas it's unlikely that we will ever be given that opportunity. But that being said, we are moving forward on making the product work together better while enhancing those areas that we think will be strategic in the future.
This is why we invested in Knowledge-Based tools and one of those projects involved enhancing Expressions so that they can and do provide Knowledge-Based functionality directly to the user without the need for conventional programming. And since Expressions drive the size and shape of the model itself, it's the foundation for much of the parametric and feature-based nature of NX.
As for Attributes, their traditional role has been to both collect non-geometric information and data inside of NX and to share it with other applications.
Now it's true, that unlike Expressions or the Knowledge tools, Attributes have not seen any recent enhancements or changes, but that will soon change as there is an effort currently underway to reengineer the Attribute layer and make it more accessable and usable with ather aspects of NX as well as external applications. Now this will not be seen for a couple of releases yet, but the work is underway and it will payoff soon.
John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA