There are a bevy of application packages out there to help accomplish your task, with more software being created and published every day. If your company is a small one with a low budget to work with, then that obviously sets the stage for your purchase options. Your platform of choice is another thing to consider. If you're strictly an Windows/NT shop, then one of the packages running on that platform may be the way to go. PCDMIS has been around for several years and does provide some creation tools to accommodate the various states of manufacture that you speak of. Once you've downloaded an IGES model, you can create additional features to some extent. Brown & Sharpe is coming out with what looks to be an excellent package called XactMeasure that you may want to look at. Again, it's an NT based software that has some excellent manual measure capability, and it features and icon based interface, which looks easy to use from the demos I've seen. B&S strengths lie in their ability to connect directly to the cmm controller, thus by-passing the native software of the machine. Of course, if analyzing parts to the ASME standard is of paramount importance to you, it's hard to argue about the robust capability of the Valisys analyze engine. Valisys is the current tool of choice here in my group and we've had excellent success with it for quite some time. We use the embedded version, running in CATIA. We use both engineering released models and our own models we create from paper drawings, which gives us the opportunity to model up whatever we need to support the programming task. Valisys has "offset" features that allow us to model up a "plus material" stock condition if we need to, using the nominal engineering model. Bottom line - do your homework, figure out how much you have to spend, and then jump on the internet and check 'em all out! :-)