Chad Jackson

The Need for Validation in MBE Initiatives

July 10, 2019

What is model validation? How does it fit into Model-Based Enterprise (MBE) initiatives? It is actually more important than you think. Chad Jackson provides an overview of this complex topic in our latest video.

The Need for Validation in MBE Initiatives


What is involved in the validation of model-based enterprise initiatives?

Fundamentally the idea is that you’re going to be taking a model-based definition (MBD), which is your 3d model plus GD&T annotations (a lot of non-geometric information) and export that into another format so that other people, such as those down the supply chain or mainstream consumers, can use it in their own processes. During that conversion process, different software applications use different levels of fidelity to define the geometry. As you convert from one level of fidelity to another, the properties of your project will change, however small they may appear. The idea of validation is that you can check the original design against derivative definitions in order to verify their congruency.

This process is very important today, as a lot of tooling is designed directly off of the 3D model. Small changes there can actually affect your tooling, which in turn will affect the parts that you manufacture using that tooling. That could end up increasing nonconformances if something is changing a little bit and doesn’t match within the tolerances that you’ve defined. Interestingly, if you think about the 2D drawing approach to MBD’s, this wasn’t as much of an issue. This is because a component drawing has three views: an isometric type of view, a closeup type of view, or a cutout type of view. The idea then was that you dimension everything to geometric could locate everything. People look at those dimensions and traverse them to get out to a point, possibly further out on the end of the component.

Even if there were small changes in the lengths of the 2D entities, it doesn’t matter because they are a dimension anyway. But in reduced annotation initiatives, whether it’s with a 2D drawing or the 3D model, you rely more on the inherent definition of the geometry instead of dimensioning everything out. As a result, engineers are having to do less work when documenting their designs. They can rely on the definition of the geometry instead. As people migrate to that, whether it’s with a 2D drawing or with a 3D model with a model based definition, you still have this validation issue. In both cases, even if you’re going out to DXF, DWG, another jpeg, or another type of additional format for the drawing, you still need to validate that the length of an entity is the same as it was in the original. For the 3D model, when you go from the original to other versions, whether it’s JT or 3D pdf, you must make sure that it agrees with what you originally designed.

That is the fundamental issue validation and model-based enterprise initiatives are trying to address. These models must line up before you get to the end of product development, or else you start getting parts back. You don’t want to have nonconformances or false positives with additional quality and inspection services to perform. That’s it. Take care and talk soon.

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