There are about as many opinions on these subjects as there are engineers in the world, but I'll share my experiences with you having set up 3 part numbering and document control systems at various companies, all of which are still in use after 15+ years.
The first thing I recommend is getting a copy of the book Engineering Documentation Control Handbook by Frank Watts. Its a very straight forward guide to setting up a system that maximizes communication between Engineering and the rest of your company without hurting your efficiency. Second, I advise you stay as far away from intelligent part numbering systems as you can. No matter how smart anyone in your company thinks they are, no one has a crystal ball. Intelligent part numbering systems almost always break down after a few years of use due to the evolution of the company. Every where I have worked, we have started out making widgets A, B and C. Within a few years our business had evolved to make widgets E thru M. If we had an intelligent part numbering system, the system we set up may have been fine for widgets A, B and C, but totally broke down when we started making widgets E thru M.
The part number classifications I use now are as follows. Each project or end item product has a unique part number that looks like 10-XXXXX-XX. Every subasembly that goes into an end item shares the same first 7 digits with the end item and is appended with an alpha character and number, like A1 or C3 for example. This ties these subassemblies to an end item or project but also allows for a great deal of flexibility. Individual parts fall roughly under one of two categories, 30- or 40-. I say roughly because 30- parts are generally custom made items and 40- are generally off the shelf items. It's important to keep the "roughly" and "generally" in there because, particularly at small companies, parts can go from custom made to off the shelf and you don't want to have to change the part number just because of that.
For part descriptions, I try to reinforce the "noun first" principles. That means the first word in a bolt description is "Bolt", not "1/4-20" or "Grade 8" or something like that. You may already know about all of that because that stuff is pretty old school but still very applicable. This, coupled with non-intelligent part numbers, puts a heavy reliance on our drawing and part number databases. If you're not sure what the part number is and you don't know what the whole description is, where do you start; with the first word that comes to mind, i.e. "Bolt". If you're looking for a subassembly, you almost always know what the end item part number was, so you can quickly bring up all subassemblies that went into it.
As I said at the start, there are a ton of opinions about this out there and its pretty obvious I've got my own. i'm sure some other folks will weigh in on this, but I hope this helps you some.
I really appreciate your input and I will definitely check out that book. For whatever its worth, I am pushing for unintelligent but have some convincing to do.
Some questions regarding your system:
- Does your top level project/end item use the last two digits or is it just 10-XXXXX? If it does, what do these end digits represent?
- What are your subassemblies physically based on? Are they assemblies you can stock on your self, or conceptual assemblies?
- Do you have more than 9 classes? Is this why you use two digits for the prefix?
- How do you assign the sub-assembly suffix? Are they simply assigned in order? A1, A2, A3...Etc
- Are you saying there is no numerical connection between a part and a project?
- Do your parts use the two digit suffix or are they just 30-XXXXX?
- Is your revision built into your part number or description? 30-XXXXX-1 BRKT-LEFT or 30-XXXXX BRKT-LEFT (REV1)
I hope you realize how much potential influence you have over the companies sanity for the coming 20 years .
Correction from question 2. Are they assemblies you can stock on your shelf or conceptual assemblies.
Here are the answers to your questions.
1. The two digits after the second dash are included with every part number, end item assemblies and individual parts. These digits are used to signify configurations of a part or assembly; or "same as except". The drawings use the same first 7 digits as the parts depicted.
2. Our subassemblies are actually both, ones we stock and ones where it just makes sense to break the production process at. Using the subassemblies makes it faster to come up with different versions of products, which we do all of the time.
3. When I started at the company I'm at now, the 10-, 30- and 40- classes were already assigned as I noted before. But, there were about 15 other classes in use as well which I made obsolete.
4. Subassembly suffixes are assigned in a tree-like manner. The trunk the tree uses A1, A2, A3 and so forth, with the number going higher the further down you go into the BOM. Then each branch uses B, C and so on, again with the number going higher the further out you go.
5. There is no numerical connection between a part and a project. This allows you to reuse parts on multiple projects with no issues.
6. See answer to question 1.
7. Revision levels are not built into the part numbers. After reading Frank Watts' book, you'll understand why.
I'm glad to help and please get other perspectives on this issue if you can. This system, as I said, has worked great for me for the past 20 years, but I'm sure there are other ways of doing this out there that have been successful too.
Again Joe, thanks for taking the time. I am a little disappointed that there were no other responses to this post. Perhaps I scared them off when I asked them not to bring up PDM
I have read the part numbering section from EDCH (which is an awesome resource thanks) and I think that I understand his system, although I am still confused about yours.
His is XXXXXX-XX where the final two digits are what he calls tabs, which sound pretty similar to revisions to me. He says these include Document Similar Items, Changed with Non-Interchangeable Itesm and Item Version Number. If I am understanding this correctly, if I have a part 123456-01 BRKT-LEFT and I end up using the same bracket for another customer who needs it painted blue rather than grey, I call it 123456-02 BRKT-LEFT. Dont I still need two separate drawings to communicate this?
I absoloutely agree with Joe's comments regarding the suggestion to stay away from over-assigning "intelligence" to the system and also the suggestion of not including the rev level as part of the number.
Without going into any detail - what is the main objection to pdm? If it is cost, Workgroup PDM is included (free) with the Pro/Premium versions of SW. Sorry, but it can be a major benefit.
I see the final two numbers as similar to configurations. Variations on a theme, not revisions.
You could use a family drawing for parts with multiple colors or other variations that you can include in a table.
Good Morning Cam,
I agree with Joe Miller that if you have 10 engineers in a room, you will get 11 opinions on this subject.
Over my career I have designed industrial products that are built and tested within the same company. These products consist of mechanical, electrical, optical, and software items on the Bill of Materials, as well as assembly and test documentation. So part numbers and revisions typically become the common language between departments. While I have not read EDCH by Frank Watts (but plan to), I have worked with three types of part numbering systems and prefer the semi-intelligent part numbers. Having said all that, here are my thoughts.
1) Research shows that a ten digit number is typically the maximum number of digits that can easily be remembered, that's why telephone numbers are ten digit (3-3-4). Part numbers that employ a 3-4-3 system (class-family-item) tend to work well outside of the engineering department because they narrow the description from the general to the specific. Additionally, classes are grouped on the BOM which helps operators find what they are looking for, in part due to the predicable structure.
2) The product line here is a baseline system that is customized for specific customer applications, therefore, our R&D activities are project based, but our "released" product is not. A significant objective in our company is to reduce cost by re-using as many existing parts as possible, this works well with our industry, but could cause limitations in others.
3) Currently we do not use a PDM system either, so our folder structure on the company network is fairly simple. Our main folder (named SolidWorks) contains a few sub-folders and the following SolidWorks files: parts, assemblies, drawings. SolidWorks files in this main folder must comply with the company part number system (we use the part number for the file name), but can be engineering revision or Production revision.
The sub-folders are:
_Datasheets: we store vendor datasheets here for "off the shelf" purchased parts
_Standards: we store industrial and customer standards here
_Vendor_models: we store 3D models of "off the shelf" parts here that do not get company part numbers
_PDFs: we create PDFs of drawings for other departments so that the native SolidWorks files are change controlled.
_Previous_revisions: when a model is changed and the revision bumps, we move the "old" revision to this folder
_Projects: this folder contains sub-folders of design projects based on customer names and product
4) I recommend keeping the classes simple, Corporate, Mechanical, Electrical, Optical, Software, Processes. Within each you might consider Electrical-Mechanical, Optical-Mechanical, Fasteners, etc. I tend to not separate manufactured and purchased because I seen too many situations where we had to bring a vendor part in-house because it went obsolete. Truth be told, there are really only two types of parts; the ones where the Vendor controls the design (off the shelf) and the ones where the company controls the design. We use revisions to indicate company design control or vendor design control. Revisions A-Z are Production items (controlled with ECNs), revisions 1-99 are engineering items (controlled by R&D) and revision PS for Vendor items.
5) Our folder structure does not breakout classes; we keep all SolidWorks files with company part numbers in one folder to minimize the folder structure effect on SolidWorks performance. As far as searching one big folder for part numbers, we have invested in training our people to use the search engine in Windows and its capabilities.
6) During my engineering career I have seen abbreviations break down to two groups, General and Industrial Specific. For the general list, I recommend using ASME Y14.38. As you have already guessed, Industrial Specific is going to depend on your industry. As for format, I agree with Joe Miller; noun, modifier, modifier.
7) I like having all our parts with company part numbers in one folder, I think that the key to making this work is improving your skill set with the Windows search engine.
I hope this is helpful, but it's just one person's perspective. I know you will create a good system for you, your company, and your customer. Best of luck.
I re-read this thread today and realized I never thanked you for your advice on folder structure. Since this discussion a year ago we put all of our released solidworks files into one folder and it has been a treat to work with. I now cant believe that we did it by project folders at previous companies.
We actually decided to put everything in that one folder (datasheets, pdfs, boms etc) and so far its worked great.