In one of yesterday's posts, the topic of intelligence in part numbers was mentioned. In the late 70's I went to work for a bio-med equipment company owned by one of the largest medical consumables companies in the world. We were the only experience they'd ever had with an electronics equipment manufacturing company. The part numbering system was one "invented" by the chief engineer based on his religious affiliation (as Dave Barry would say "I am not making this up"). It was a 12 digit number separated by dashes into groups of four. The first four defined the category. 0799 and down was for purchased components. If it was above 0800, it was for custom parts or assemblies and there was a different set of rules defining the assignment of the remaining 8 digits. The second set of four digits was the modifier. 123 changed for each new part of assembly and the dreaded 8th digit changed depending upon what you were dealing with. "0" was the part, "1" was the mechanical drawing, "2" was schematic, etc. You get the picture. The last four digits were the revision. The second digit in that series would advance if the change was a "major" change, and the last two advanced on a "minor" change. The rules defining major and minor also changed depending on what the 8th digit was. The component (0799 and down) numbering contained significance. A capacitor would be numbered based on voltage, rating, etc., but little things like case sizes and styles were ignored. So, the floor never knew whether they would receive axial or radial leaded parts and what size they would be. Now think what the poor person in receiving inspection went through trying to identify and stock a part, then what the floor went through trying to define their documentation and processes. Nightmare didn't begin to describe it. The chief engineer continued to defend the system even though the entire engineering department hated it. The system was finally abandoned after the parent company installed new top management and there was an absolute revolt from the manufacturing floor management. Has anyone else worked with a worse system? Bob Croslin Nielsen Media Research -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of TDK Sent: Tuesday, October 11, 2005 8:30 AM To: [log in to unmask] Subject: Re: [TN] Assembly Documentation Question You already have that matrix. It is call the BOM (Bill of Material) The BOM lists ALL the documents ( & their REV's) which the PCB Assembly you hold in your hand was built to. The PCB assembly will need to have the PL Rev stamped, which it was built to ( so that ongoing repair & maintenance people ) can pull up the BOM it was built to & work to that. Even the test procedure rev will be listed. Each document should be allowed to change on its own ( That is why we have Rev's, isn't it ??? ) Adding these sub-suffixes, is something my outfit also started doing & its just another way to trip ourselves up on. I don't agree with it. That is what the REV is for. REV A, B, C...... but not REV A1, REV B3... What companies should do, as a starting exercise, is to develop a matrix with all the possible changes listed ( we already know what that is ), then go thru the paces. In my way of thinking, the BOM is the ultimate controlling document ( the MATRIX ). Regards TDK -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Nutting Sent: Friday, October 07, 2005 11:23 AM To: [log in to unmask] Subject: Re: [TN] Assembly Documentation Question Michael, My experience and preference is to have the BOM and assembly drawing match in revision. If they don't match who is going to maintain a matrix explaining what document goes with another document. Does your BOM call out the revision of the assembly? If so wouldn't you have to uprev the BOM to reflect the change in revision of the assembly print? We experimented with making "dash" prints where we started with a "generic" design with a -X suffix and then for subtle changes made -1, -2, etc. assemblies but all based upon the -X print. You wouldn't believe the confusion this caused at outsource vendors and our revisions. Imaging the problem when the assembly print and BOM revs do not match. I... Can... Not... Change! Must... Do... It... the...way... I... Have... always... Done... It! Wow that was close. Phil -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Michael Kuczynski Sent: Friday, October 07, 2005 12:19 PM To: [log in to unmask] Subject: [TN] Assembly Documentation Question The company I work for is going thru some documentation change discussions. Below are the documents that are revisable. (The parts list contains all the IC's, cap, res. etc. and documents.) The feedback I'm getting is the the parts list and the assembly drawing should ALWAYS be the same revision (becasue thats the way its always been). Everywhere I've every worked, these are independent documents. Here are my scenerio case: (All documentation released at Rev. A) Scenerio (Rev: B): A part number change, of a 1K, 5% resistor to a 1K, 1% resistor. In this case, the part list and schematic would change, but it has no effect on the assembly (because no part number or value is on the assembly drawing). PL1234567-1 Rev: B Parts List AW1234567 Rev: A Assy Dwg DS1234567 Rev: A Drill Dwg PC1234567 Rev: A Artwork PA1234567 Rev: B Schematic Scenerio (Rev: C): The length of the screw holding the stiffener bar is changed from 3/8 in. to 1/2 in. The change is to the parts list only, the assembly drawing stays the same. (no 3D view or side view) PL1234567-1 Rev: C Parts List AW1234567 Rev: A Assy Dwg DS1234567 Rev: A Drill Dwg PC1234567 Rev: A Artwork PA1234567 Rev: B Schematic The current discussion and question is; -Can the parts list be independently revisible, from the assembly drawing? -What do most of the assembly houses usually like? Thanks for any response to this question. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- [log in to unmask] --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------