From the instructions, it seems that it is a lot easier to create a new number sequence for an object via a non-modeled datastore sequence than a modeled datastore sequence. The thing that concerns me about the non-modeled sequence though is in the help instructions it says "When a non-modeled sequence is created, the database schema objects are not included in the Windchill introspection information. Therefore, some tools that rely on this information (e.g.Windu, upgrade tools) will treat these objects as unrelated to Windchill." Does this mean that there are problems when you do an upgrade, like from 10.1 to 10.2? Would you have to recreate them?