From a business standpoint, Siemens should support migration of other CAD format files into NX and then allow feature editing in NX. This migration tool should not be designed for daily moving of files between 2 systems because one is easier to use, less busy, etc.
Multi-CAD environments do have their purpose but for a design tool internally, you should have one system that is your primary tool. The other systems can be used to interface with outside suppliers who do not utilize the same tool you do. I worked for an aerospace company a few years ago and we standardized on Pro/Engineer as the division's primary CAD tool. Being CAD support, I also had NX, CATIA V5, SW, AutoCad and Inventor on my computer. Yes we did some projects in those other systems due to budget or time constraints, but we also knew that what they produced would never be integrated with a master Pro/E model.
I do agree that when a model is imported into NX, any changes on the model should be reflected in the NX file the next time it is opened. I do think that is how the NX-SE interface works and it should do the same with NX-SW, NX-Creo, NX-Catia, etc. Editting the imported model with features should not be done with assembly importted components. If the decision is made to 'transfer' the design control from one of those other systems to NX, then the NX Migration utility comes into play and now NX has model authority.
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