2D CAD vs MBD: Challenges in Reading Many-facets of Design Interpretation

In the age of 3D CAD model annotations, there still exists manufacturing organizations and manufacturers who are not even close to dropping 2D manufacturing drawings for daily shop floor operations.

Let us revisit the challenges and the psychological abilities for design interpretation that are needed to a shop floor foreman in extrapolating the actual design intent with 2D drawings by the engineers. Below is a comparison of psychological interpretation of design features while manufacturing with 2D and MBD.

Gleaning 3D orthographic designs from 2D views

When the manufacturer relies on 2D drawings, it is essential to have at least three views for a single component or a part to put down the complete design information in drawings. In case of complex multi-component assembly, the number of drawing views reaches 4-5 or even more in some cases for showing sectional drawings to specify the dimensions of internal parts. Naturally, it increases the ROI as the time consumed to create and interpret the drawings increases significantly.

Now understanding 3D shape from 2D drawings takes an immense amount of extrapolation to know what part is being manufactured and match the original design intent of the manufacturer. Extrapolation not only means interpretation of design intent but also the assurance of the fact that everyone on the product development team must be able to perform their tasks based on that 2D drawing. Furthermore, it also includes ability to prepare downstream documentation whatsoever needed.

Psychological abilities to interpret 2D and the risks involved

Psychological abilities here encompass only the definition of spatial intelligence – a popular term amongst psychology enthusiasts – to imagine the 2D drawings. Now when design engineers use 2D drawings to communicate manufacturing information, need for spatial intelligence becomes imminent.

Every stage including manufacturing, procurement, quality controls etc. will need the skills and only the professionals in these fields will be suitable for the jobs. This narrows down the choices for the manufacturing organization to hire from a small pool of probable candidates; or alternatively will have to provide rigorous training to new crops. Either way it takes too long and monetary investment is too much.

Additionally, despite the training and time investment, there is no surety that the drawings will be interpreted correctly. As such, most manufacturing professionals commit severe mistakes, however small, but it proves to be costly even after having a considerably long work history. And above all this, the design intent presentation to the client in 2D is always a tedious job. Design changes, too, are manual in 2D and a never-ending process.

Applying spatial intelligence to MBD

MBD deliverables sharply contrast 2D CAD drafting and drawings. Since MBDs convey detailed manufacturing information about the component, part or assembly in 3D, the geometry defines the design intent well. Going further, with MBE and MBSE, a larger part of the product team would be addressed with a single file and need of extrapolation based on psychological information is reduced drastically. The need for additional documentation for any other functional engineering team is eliminated completely.

The need to reconstruct the entire component geometry in the head of the manufacturer based on 2D information vanishes with MBD. A 3D model can be spun, rotated, interrogated from different angles, analyzed through simulation and much more. However, it’d be a hype to say that spatial intelligence is eliminated completely. But it is significantly lower as compared to that in 2D which gives a broader selection pool to manufacturing firms for selecting the right people to work with.

What should be your opinion as a manufacturer?

Now as a manufacturing organization, your taskforce has been using 2D for a very long time and perhaps is still using it. And interpolation in using 2D along with the extrapolation remains a vital part of its job roles. And to manufacturing taskforce, it appears as if MBDs are snatching away interpolation (a part that is vital) from their job role.

And on the other hand, even with MBD, you cannot assure the quality standards just like in 2D and psychological design imagination is also not completely eliminated. Plus, tolerances and annotation layers are also added to the design model which requires larger storage space. Which one do you prefer?

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