Effectively Working with Part Numbers and Standard Libraries Alongside SOLIDWORKS

Naming conventions are often regarded as simple and fairly straightforward. I submit that there’s real value in thoroughly discussing and investigating the impact of the numbering sequence and structure utilized. While I’ve had quite a bit of experience in this arena, I’ve yet to find the perfect system. Even starting at “1” and incrementing from there has it’s issues. Read on.

First, some science on numbers and how humans are able to digest them. Back when the telephone was the latest and greatest invention, humans operated switch-boards to route calls as requested. Soon came the rotary dial telephones enabling users to call others on their own, without a human-powered switch-boards. With this invention came the need to standardize on the phone number sequence across the board. Alexander Graham Bell enlisted the help of Professor George A. Miller (1) who was performing landmark research on human memory retention at Harvard University. Professor Miller was deep in study preparing to write his paper on memory entitled, “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information” (2). He established that for humans to remember a number, seven numbers chunked into two sets (three and four) was ideal. As the proliferation of the area-code became a necessary reality, it was found users could memorize and recall common area-codes with ease and concatenate three then four more digits on the end with minimal effort. For example, how easily can you read 4825784806 as opposed to (482) 578-4806? How quickly could you read and repeat that same number to someone over the phone? Verbally? Read and write it down on a piece of paper?

You might be wondering, “What does this have to do with SOLIDWORKS?”. Well during my various consulting travels, I’ve discovered there are primarily two industry forces that have driven and formulated the two base numbering strategies, products and projects. Regardless of what camp you may find yourself primarily in, I’ve rarely found an organization exclusively using one. It’s almost always a hybrid system of sorts.

  • Product-based organizations typically tend to maintain vast libraries of “families” of parts, commonly using prefixes (area-codes) to denote the family, then sub-category (first set of digits), sub-sub-category (second set of digits), and so forth. This strategy is commonly referred to as “Smart or Intelligent” part numbers as the numbers can actually be used to describe the file in which they represent.
  • Project-based organizations typically incorporate a unique identifier to all files on a given project (commonly prefixed with the project number), working to maintain which files are for what projects and help keep all the right files in the right folders. If you find yourself copying files from one project to another and making no changes, perhaps it’s time to establish a product-based family line of internal standard components.

Both of these approaches are quite practical and, depending on the other tools present or deployed (ERP, PDM, PLM, MRP, etc.), do assist downstream in the execution of manufacturing, assembly, stocking/inventory, shipping, etc. They also, however, both have their drawbacks. Here’s a cursory list of commonly encountered challenges. It’s important to note that, depending on your situation, these discussions can quickly become complicated.

  • Drawings are still necessary for most all SOLIDWORKS applications (until Model Based Definition (3) catches on that is). The windows file structure (and every PDM product I’m familiar with) will prevent the exact same file to be saved in the same folder. This forces uniqueness and prevents the creation of two 123-4567.sldprt or 123-4567.sldasm files. It’s possible, however, to create both a 123-4567 part and assembly file (This causes an issue because only one drawing file named 123-4567.slddrw may exist). I’ll often see assembly and part files having different naming formats/designations, or an established process where users are extra careful to confirm the number is not already being used by another file type.
  • Regardless of the procedure, gaps in your part number sequence are likely to happen. Should you work to fill them or not? Do you want the higher numbers to be newer parts? Do you want to keep the size of your numbers as small as possible?
  • No matter your opinion on configurations, they tend to be utilized in most every organization for various reasons. Anytime there’s a single file representing several unique parts or assemblies, difficulties ensue. What is the file called? How user friendly is it? How do you train users to know what file to open to find the data they are looking for? Certainly a well-implemented PDM/ERP/MRP solution may help minimize such inconveniences with relationships and searching, but the struggles are real. While not fool-proof, the best I’ve seen is to work towards maintaining a “master” file name and add a sub-category, if needed. For instance, if I’m modeling a brace that needs 5 different configured lengths, pull a “normal” number (in either format) and add a -X or similar placeholder to the end of the file name indicating that it’s a configured file. The configurations can then be thought of as “derived children” of the “master” file. If the drawing file is always given the proper representative name, users can be instructed to open the drawing first and then the solid model via the drawing (when practical).
  • Every organization I’ve worked with utilizes purchased commodities in their design to some extent, and usually managing those standards and library files is last on everyone’s list. Storing the purchased commodities under their (current) vendor, manufacturer, etc can get complicated. Additionally, some companies heavily rely on spare/replacement part sales for revenue and work diligently to maintain the confidentiality of their suppliers. Others incorporate the manufacturer (example SMC) and their part number (example “12L-2 0A-M9NSAPC4”) together (SMC-12L-20A-M9NSAPC4) to make it easier for everyone.
  • Let’s imagine you need to incorporate an electrical cabinet into your design and you use the standard EC-57EI583 (diagram below) from your Standard Purchased Parts Library. It needs to be modified for your particular design by adding an HMI cut-out in the door. I would propose to create an assembly in accordance with your project or product numbering requirements, insert the single component you wish to modify and then make the needed changes at the assembly level. This effectively transforms the original purchased commodity, via the assembly, into the new number specific for your needs. I’ve found this to be a superior solution versus creating copies of the original per project. It’s difficult to effectively source and manage the purchasing of the base commodity when listed as a material and the tractability through the BOM isn’t available.

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In the end, I generally favor a numbering schema that generally adhere to following rules:

  • Limited use of alpha characters – It makes reading more difficult (0 vs O, 1 vs I, etc.) and not as fast to type in (entire keyboard vs 10 key pad)
  • Utilization of smart/intelligent numbers where practical – Depending on your product vs. project environment, practical family based, prefixed (area-code) numbers are a good place to start
  • No leading zeros (Example 005-4032-4)
  • Heavy utilization of dashes (other symbols can be used but aren’t as clear or 10-key pad friendly) to “chunk” longer numbers into more human amicable
  • A defined strategy on:
    • Filling number gaps
    • Configuration usage
  • Implementation of a well-documented purchased commodities library
    • Purchased commodities modification methodology
  • Acknowledgment that no system is perfect, anticipate anomalies and plan for how to handle them
  • Above all, document policies, procedures and thought processes around desired outcomes

Some of us are provided the freedom to select our own numbering schema, others need to live inside the confines of our employment, still others have the privilege of establishing, defining and directing standards inside a given organization. I hope that some of the topics covered here provided some good talking points to start from, fully recognizing this is a complex topic but often necessary to maintaining a long-term, sustainable and organized numbering structure.

Next up, properties! How, when, where and what to say. Stay tuned!


1. https://en.wikipedia.org/wiki/George_Armitage_Miller#Legacy
2. https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two
3. https://en.wikipedia.org/wiki/Model-based_definition

Andrew Schutte

Andrew Schutte

Andrew is a 10-year seasoned SOLIDWORKS designer with experience in a variety of industries including automotive, furniture, consumer product, food and beverage. He enjoys solving a wide range of complex problems relating to SOLIDWORKS and manufacturing environments. Andrew has used SOLIDWORKS since 2004 and served in a variety of roles relating to SOLIDWORKS. Including working as a SOLIDWORKS Mechanical Engineer, IT Administrator, CAD/Engineering Administrator, Software Development Manager (for SOLIDWORKS integrated products) and adjunct professor teaching practical application of SOLIDWORKS Mechanical design.