If you’re around NX for very long you’ll hear someone talk about the Master Model concept. It is an important concept. It comes up in the various forums from time to time. Usually when people as, What is the master model concept? There are no shortage of answers offered. But I feel that most of the discussions miss the mark. I think there are a lot of misconceptions about the Master Model Concept. I am going to try to clear some of them up.

Master Model Definition

If I’m going to discuss what people get wrong about the Master Model Concept, I should at least try to provide a definition of what it is. Here is how I define it

Master Model Concept:

A method of separating a CAD model definition from data which is dependent upon the CAD model but does not define the CAD model itself. This separation is achieved by storing the CAD model definition, called a Master Model, within one file and each piece of dependent data within separate files which refer to the Master Model, typically by including it as a component within themselves. Typical examples of dependent data types are drawings, machining tool path definitions, and FEA analyses.

Now, on to the misconceptions.

As I’ve mentioned before, Multi-key identifiers in Teamcenter was a feature that many of us have been waiting for. It was originally rumored to be coming in TC 9, but that didn’t happen. Fortunately, it did make it into Teamcenter 10. Some customers have begun testing it in the pre-production version 10.0. I haven’t had a chance to work with it myself yet, but I’ve been studying the 10.0 documentation to learn what I can about it. The documentation refers to the new feature as, multifield keys. Here is what I know.

A commentator on my earlier post about CAD-BOM Alignment asked a question for which I don’t have a good answer, so I’ll share the little I know and perhaps in the comments section someone who knows more about it can fill in the gaps. First, here’s Dan’s question:

I’ve been asked recently for my thoughts about where custom data should be stored in Teamcenter. Should it be stored on a Master Form or in object properties? So, I thought I’d write something on the subject. I also would like to hear what other TC developers are using and what pros or cons they’ve encountered.

If you work with BOMs in Teamcenter you have probably seen the terms Precise and Imprecise BOM structure. Even if you only use one type of BOM you need to understand the difference between them.

If you’re using Teamcenter to store your CAD models and drawings (and most Teamcenter customers are, I believe) then one of the first issues to tackle is, how do you store those drawings? There are a few different ways I’ve seen: embedded in the CAD model dataset itself, stored as an additional dataset under the same item revision as the CAD model, and stored as a separate item from the model item. Today I’ll run through some of the issues related to each of these approaches.

I’ve been reading up lately on the differences between Product Data Management (PDM) of CAD data and Product Lifecycle Management (PLM) of part data. I must confess that I used to think of the difference between them as one of degree and not of kind — that PLM was basically PDM on steroids. But more and more I’m coming to the conclusion that I was simplistic in my understanding. The truth is that they are different tasks altogether. Because of this misunderstanding I came up with some very inelegant solutions to some of the data management issues I encountered. I have been looking for better solutions. As it happens, it seems that Teamcenter now provides us with a means for making this distinction between PDM and PLM by maintaining two independent structures, a CAD BOM of Design items and a Part BOM of Part items, and then aligning the two. Although I have some concerns with the process, I think it has potential and should be explored.