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Managing Engineering and Manufacturing BOMs in PDM

Question asked by Craig Merrifield on Feb 22, 2017
Latest reply on Jan 20, 2020 by Jason Capriotti

We are trying to nail down a process for managing both Engineering Bills of Materials and Manufacturing Bills of Materials using SolidWorks PDM Professional and I am seeking wisdom from my fellow PDM admins and users. The solutions illustrated below include the use of many of the following functions in PDM Pro. Please note that a solid understanding of these functions is necessary to make sense of the rest of the post…

  • SolidWorks Computed BOM
  • SolidWorks Dummy Parts (SW parts with no features/content, but include custom properties)
  • PDM Paste as Reference (to relate non-SW files to the assembly or components in the computed BOM)
  • PDM Virtual files
  • PDM “Items” (PDM Item Explorer)
  • PDM Named BOM

 

Initially we plan to create the Engineering BOM which is intended to be all inclusive. The structure of the BOM will include any/all documentation related to the product including basic things like models and drawings, but additionally things like material specifications, manufacturing assembly instructions, product instruction sheets, graphics, legacy CAD files, labels, adhesives, packaging materials, etc…

 

The Manufacturing BOMs that we’ll create are simply a sub-set of data from the Engineering BOM (only what is actually needed to build the product on the manufacturing floor). The creation of these Manufacturing BOMs will always follow the creation of the Engineering BOM. The Manufacturing BOM could then be exported to ERP/MRP system.

 

Facts:

We ARE using configurations in parts and assemblies

File names cannot be based on part number because our configurations represent one part number per configuration. If each file contains multiple part numbers, the file cannot be named on this basis. Instead file names are based on a serially generated number for each file. Configurations ARE named based on the part number. Configuration specific tabs are used to contain the relevant information for each part number.

We ARE using drawings with tabulations

File names cannot be based on part number because our tabulations each represent one part number. If each file contains multiple part numbers, the file cannot be named on this basis. Instead file names are based on a serially generated number for each file (same as above). Each tabulation is given a new sheet on the drawing (blank sheet). Each sheet is named based on the part number. Sheet specific tabs are used to contain the relevant information for each part number.

We ARE NOT using lines added to Named BOMs as that information is not searchable using PDM search tools.

 

Challenges:

  • Paste As Reference (PAR) is not configuration specific. The file reference creates a file level relationship, but not at the configuration specific level.
  • Circular references can occur if a PAR is used to create relationships to between SolidWorks files that may or may not be desired in the natural Computed BOM. (I am aware that this is bad practice and is not recommended)
  • Quantities of some materials need be fractional or less than “1”. For instance, if paint is used, the quantity of might be 2.5 ounces. I am not aware of a way to reflect a partial number quantity using PAR relationships, “Item” relationships, or even with Dummy Parts.

 

Essentially, we are trying to decide between two strategies that we’ve assembled. I’ll do my best to outline them below.

 

Strategy 1 – Computed BOMs

Building the BOM Structure:

Start with the computed BOM that is naturally created when a SolidWorks Assembly is built. Use PAR to attach file references to the SolidWorks Assembly and Parts. Using PAR allows us to leverage the Computed BOM structure by attaching additional files (along with relevant data) to it. Once all PAR relationships have been created, the Computed BOM becomes the backbone of the Engineering and Manufacturing BOMs. Use of PAR is required in strategy 1 to create the BOM structure. In the case where a file does not exist, PDM Virtual files can be used to store data (in the datacard). This could be a permanent file in the BOM structure or simply a placeholder until the desired file is completed.

 

The Engineering BOM:

Once the Computed BOM is fully populated with PAR relationships, a PDM Named BOM will be created (as the final level) to manage quantities as they CAN be manually adjusted to partial numbers here.

 

The Manufacturing BOM:

Once the Engineering (Named) BOM is completed, it can be copied to create the Manufacturing BOMs. Quantities can be adjusted and items that need to be removed from the BOM can be “hidden” (the line is “hidden” as it cannot be deleted). Multiple Manufacturing BOMs may be created as we have several manufacturing locations and assembly processes sometimes differ from site to site. One challenge faced here is the behavior of the Named BOM when updates occur. When an update occurs in a Named BOM, any lines that have been “hidden” reappear. This forces the user to re-hide the undesired lines.

 

 

Strategy 2 – Item BOMs

Building the BOM Structure:

Start with the computed BOM that is naturally created when a SolidWorks Assembly is built. Paste As Reference (PAR) can be used in Strategy 2, but is not required. PDM “Items” are created for each part in the BOM. Natural references that exist in the computed BOM can be inherited at the “Item” level and new “Item” relationships will be added manually with the other “Items” to create the “Item” BOM structure. These “Items” can be tied to files in PDM and can have data propagated to the “Item” data card from the file, or they can be stand alone with no tie to a file in PDM. (Our preference is that every “Item” is tied to a file, virtual files are acceptable.) The completed “Item” BOM becomes the backbone for the Engineering BOM and Manufacturing BOMs.

 

The Engineering BOM:

Once the “Item” BOM is fully constructed, a PDM Named BOM will be created (as the final level) to manage quantities as they CAN be manually adjusted to partial numbers here.

 

The Manufacturing BOM:

Once the Engineering (Named) BOM is completed, it can be copied to create the Manufacturing BOMs. Quantities can be adjusted and items that need to be removed from the BOM can be “hidden” (the line is hidden as it cannot be deleted). Multiple Manufacturing BOMs may be created as we have several manufacturing locations and assembly processes sometimes differ from site to site. One challenge faced here is the behavior of the Named BOM when updates occur. When an update occurs in a named BOM, any lines that have been “hidden” reappear. This forces the user to re-hide the undesired lines.

 

Alternative - One alternative method here would be to copy the “Item” BOM (with a new “Item” name) and remove unneeded “Items” to create a Manufacturing “Item” BOM. Then a Manufacturing Named BOM would be created to manage the quantities, but unneeded lines would not need to be hidden in the Named BOM as they were managed at the “Item” BOM level thus eliminating the challenge alluded to above.

 

 

 

Are any of you all managing BOMs in PDM to this extent? If so, I would be greatly interested to hear your process.

 

If anyone made it to the bottom of this post, understood it, and are still awake, I commend you.

 

Thanks in advance for any input,

 

Craig Merrifield

Aka Merf

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