Author: Duane Hess
I have encountered some confusion and misunderstanding around the difference between Model-Based Definition (MBD), Model-Based Enterprise (MBE), and Model-Based System Engineering (MBSE) with people I meet. The first confusion point is that all three phrases contain “model.” I will dig into that first, and that should start to shed some light on that second point of confusion in that these three terms are interrelated, but they have very different meanings and very different boundaries.
In our line of work, “model” generally refers to 3D geometry that represents a part or assembly as a CAD file. Most people can visualize this 3D model as some object or widget assembly that they can orbit around to see all the features. Those with a more futuristic bent might think of virtual reality (VR) or video games and having the ability to interact with 3D geometry. In all cases, software captures the geometry digitally in mathematical form and, in these examples, displays the model for human interaction.
In our line of work, “model” generally refers to 3D geometry that represents a part or assembly as a CAD file.
There’s a second definition of “model” that refers to a system or an example that one can follow. This meaning of “model” may also be based on mathematics but is represented through steps or procedures to define relationships. A model of this type could be as simple as recipes for baking cookies or as complex as weather forecasts. Think of flow charts or logic diagrams that describe the connection between events.
Model-Based Definition (MBD) is the practice of using a 3D CAD model and associated data instead of relying solely on engineering drawings. Using the 3D CAD model keeps the information digital to make it easier to re-use outside design departments on manufacturing floors and quality inspection areas. There are many places in an organization that can use that digital information, which brings me to the second phrase, Model-Based Enterprise.
A Model-Based Enterprise (MBE) is simply an enterprise, an organization, that has based its processes on using a Model-Based Definition, keeping the 3D CAD model at the heart of its operations.
Model-Based Systems Engineering (MBSE) is an engineering discipline in its own right that, simply put, attempts to describe how things interrelate in a predictable and controllable manner. It describes systems as methodologies, providing a framework for how things work and connect, lending control and predictability to complex interactions.
The confusion between the terms is understandable, but now that we understand the terms a little bit, we can talk about how they inter-relate.
Model-Based Definition is a part of the Model-Based Enterprise. Data from MBD may be digitally connected and re-used throughout the Design, Manufacturing, and Quality processes and in normal business areas like procurement, sales, sustainment, and beyond. We refer to this connectivity as the Digital Thread and a Model-Based Enterprise. As an enterprise makes these data connections, they become a part of Model-Based Systems Engineering to understand, control, and predict the processes that define the business.
Model-Based Definition is a part of the Model-Based Enterprise.
The analogy that I use is that of Russian nesting dolls.
The largest and outermost is MBSE. MBSE contains a smaller doll; Model-Based Enterprise. MBE likewise has a doll inside; Model-Based Definition. MBD is a part of MBE, and MBE is a part of MBSE.
Enabling Digital Twin Adoption Through a Model-Based Approach
Presented at the Digital Twin Summit 2022
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