No really, what is MBD?

There are at least 4 engineering acronyms for MBD – what do they all stand for?

Acronyms are a useful tool when talking shop with professional colleagues. With a few letters, like CAD, CAM and CAE, you can identify what everyone is talking about without using unnecessarily long terms, like computer-aided design, manufacturing or engineering.

(Image: Bigstock.)

(Image: Bigstock.)

But there is a significant challenge with the abbreviation MBD. With 26 letters in the English alphabet, there are 17,576 possible abbreviations with three letters. This gives engineers plenty of options to differentiate the numerous concepts in the field. However, despite those permutations MBD has no less than four, perhaps more, engineering definitions. Here is a guide.

Model-based definition (MBD)

A quick google search of MBD may return inks to an old article and posts from engineering software companies such as PTC and Autodesk defining the term as model-based definition.

Model-based definition is a feature in various CAD, PDM and PLM software that enables users to annotate and associate part information with a 3D model. Some of the information that might be included with this version of MBD includes geometric dimensioning and tolerancing (GD&T), material properties, bills of materials (BOMs), configurations, data, notes and more.

In essence, the 3D geometry acts as a single source of truth for everything an organization needs to know about a part. In the past, much of this data was associated with 2D engineering drawings and paper documents. However, as 3D models are better equipped at modeling real-world assets, and digital records are easier to maintain, MBD is a considerable improvement.

MBD is often used interchangeably with product information modeling (PIM) or digital product definition (DPD). It is also associated with numerous industry standards including ASME Y14.41, ISO 16792, ISO 1101 and AS9100.

Model-based design (MBD), or is it model-based development?

A Google search of the term MBD may also bring up pages from the engineering software companies Synopsys and MathWorks that define the acronym as model-based design. If that isn’t confusing enough, PTC, IEEE, systems engineering company Array of Engineers and automotive systems engineering company dSPACE use the term model-based development on their websites to describe the very same process.

Whether you call it mode-based design or development, this version of MBD can be traced back to the early history of systems design, systems engineering and process control. It involves producing a model of a complex system using flow charts, mathematical equations and simple simulations.

The model-based design process. (Image: Synopsys.)

The model-based design process. (Image: Synopsys.)

Early in development, the goal of model-based design is to quickly iterate system setups via virtual tests. At this stage, the simulations help engineers explore the design space, verify and validate final products, enhance functional safety and generate software to control the system. As this is all done digitally, systems development can be done faster and safer than if various physical prototypes were used.

After deployment of a physical system, MBD simulations are still useful. For instance, they can then be used as a digital twin to help optimize, predict maintenance and upgrade physical assets.

Multibody dynamics (MBD)

In the engineering simulation and computer-aided engineering (CAE) world, people might know MBD to stand for multibody dynamics. For example, simulation software companies such as Hexagon, COMSOL, Altair and Ansys, as well as outlets like ScienceDirect, MIT and more, have website pages devoted to this definition.

A multibody dynamics simulation of aircraft landing gear using Adams software. (Image: Hexagon.)

A multibody dynamics simulation of aircraft landing gear using Adams software. (Image: Hexagon.)

Multibody dynamics simulations assess mechanical systems made up of rigid or elastic parts. Using equations of motion, multibody dynamics simulation software numerically assesses the kinematics of each part in the system based on their mass, center of mass, inertia and properties after the application of internal and external forces or torques. The motions multibody dynamics simulations might describe span the translational and rotational movements of aircraft parts, construction equipment, robots, vehicles or any other system with moving parts. Some assessments engineers can perform using multibody dynamics include the study of noise, vibration and harshness (NVH), vehicle performance, electronic control systems and more.

Much like model-based design and model-based definition, multibody dynamics is often used early in the product development cycle to virtually test the performance of a design before any physical assets are produced. Multibody dynamics simulations can also be used as part of a digital twin to monitor and assess real-world assets. However, unlike model-based design digital twins, which traditionally assess industrial systems, multibody dynamics digital twins assess a real-world systems’ motion.

More MBD?

Other definitions of MBD exist for various engineers in different industries. Some examples include:

  • Molecular beam deposition in materials science.
  • Market-based dynamics in economics and systems engineering.
  • Minimum bounding dimension in geometry.
  • Motherboard in electronics.

If you can think of more engineering terms abbreviated to MBD, list them below.

Written by

Shawn Wasserman

For over 10 years, Shawn Wasserman has informed, inspired and engaged the engineering community through online content. As a senior writer at WTWH media, he produces branded content to help engineers streamline their operations via new tools, technologies and software. While a senior editor at, Shawn wrote stories about CAE, simulation, PLM, CAD, IoT, AI and more. During his time as the blog manager at Ansys, Shawn produced content featuring stories, tips, tricks and interesting use cases for CAE technologies. Shawn holds a master’s degree in Bioengineering from the University of Guelph and an undergraduate degree in Chemical Engineering from the University of Waterloo.