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Is CAD the center of your world? 

Consider if your company is CAD centric or BOM centric. What does that mean? CAD centric means you value your CAD as the part, the focus is on producing 3D representations of the product. The revision of the part is to be the same as the CAD. Often this practice has been driven from using file-based storage in windows explorer, where it is easier to search for one number or inadequate functionality in an existing PDM system. Comments such as "the drawing and the model are both used together to represent the same product, their revisions should track together" are fundamentally wrong statements for an engineering company.

Here is mapped the typical scenario in linking the revision and name across different item types:

Operating in this fashion will give you 2 types of risks:


1. You must revise all 3 objects if you modify 1.

An example: A wrong date, a dimension is missing from the drawing or missing associated text on a drawing will drive a drawing revision change. If you need to revise the drawing the consequence will be that the 3D will need a new revision to match, and now also your part in ERP needs a new revision.

The downstream impact: For manufacturing, consider what drawings are existing on the shop floor? What drawings are in existence with your suppliers? For the supply chain, consider the stock on order, or stock manufactured. Should it be scrapped? Can it be used as-is?

In conclusion, this scenario can cause a chain of consequences downstream that results in mess for the rest of the organization.


2. You lose track of changes.

An example: Updating a drawing without changing Rev. You may recognize the scenario... "It is only adding a small text, so we don't need to worry about 3D and we don't need to worry about ERP". So as a company an exception is made to open the drawing to make a change and keep everything the same. Shhhh no one will know!

The downstream impact may not be immediately known. For manufacturing; what drawings are existing on the shop floor? What drawings are with your suppliers? Can you really ensure your engineering office knows exactly where the drawing exists downstream in the business, and who saw the drawing in the original format. The impact in the Design office could also be unknown. Consider what will happen if the next revision is currently being worked on in 3D, now you need to be careful someone does press refresh on the drawing and update the drawing dimensions when the intention was only to update the drawing text. Now imagine you get audited, you will fail audit if even one of these old drawings is found on shop floor and it doesn't match the official released drawing.

In conclusion, you could have 2 physical drawings that have the same name but different content.


Explore your possibilities with BOM Centric thinking!

BOM centric is a different mindset, putting your product configuration front and center of your business. It is appreciating you have connected data and documents and all this data will evolve organically over time. Sometimes the changes impact other items and sometimes they will not. By focusing on the product as a whole and not solely on the CAD you can associate much more data to your bill of materials and trust the connection between objects.

What if I told you that there is a tool that allows you to do this….. This is the PLM system. 

One of the primary benefits of a PLM system is configuration management. This means you keep all objects in sync without worrying about naming conventions and complex business protocol. Information flows in a different way, metadata on objects can be passed where it consumed and where it is needed.

In this diagram, the same objects are referenced but now metadata is captured rather than a hard link of part name to drawing name. This allows a different revision sequence for the drawing and the part.

There can be independent changes on the drawing whilst keeping the part revision stable, the drawing revision shall progress to 2 or 3 or 4 and the part revision stays at A. This can allow the quality to increase on drawings without actually cycling the part definition.


Are you having similar problems in your design office? Are you sick of Engineering Changes? Would you like to be able to search for drawings on more properties than filename? If the answer to any of these is yes then please get in touch.


About the author

Leigh Young

For more than 10 years, Leigh Young has used his vast experience as a system engineer to optimize business processes, workflows and tools used in the largest global manufacturing companies. He has worked extensively with the largest PLM and CAD systems and frequently shares his thoughts and opinions on the subject.

As a functional lead in Minerva, he represents the Solution Consultant function as part of a cross-functional team.

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