Can someone explain to me the tab suffix for a part number
Can someone explain to me the tab suffix for a part number
(OP)
Hello everyone, I have been developing a part numbering scheme for a start-up light manufacturing company. From all the wonderful discussions I have read here, I have decided to go with a non-significant part numbering scheme. In the book "Engineering documentation control handbook" Watts highly recommends a "tab suffix" as the post-fix on the part number. I don't think I full grasp this concept. For example, say we manufacture a light with part number 10101-XX (xx being the numeric tab). He describes it as "The Tab is a form of significance, although minimal. It is used to delineate similar items on the same document." Can you explain this to me? Maybe an example?





RE: Can someone explain to me the tab suffix for a part number
Mike Halloran
Pembroke Pines, FL, USA
RE: Can someone explain to me the tab suffix for a part number
Mike Halloran
Pembroke Pines, FL, USA
RE: Can someone explain to me the tab suffix for a part number
Many companies are now getting away from the Watts approach and purposely have separate and distinctly different document number (revision controlled) and part number formats. Relationships between documents and parts are database-linked using 'effectivity'.
The differences between the two are really important to understand. In either case, formal policies are required if design configurations need to be managed.
Peter Truitt
Minnesota
RE: Can someone explain to me the tab suffix for a part number
Watts - A company makes an electrical panel (Doc. No 123456, Rev. C, married to P/N 123456-03) that gets a circuit breaker in a rectangular hole. The breaker is discontinued by the supplier. The replacement breaker takes a D-shaped hole. Using detail views or notes or whatever method works best, the document is revised to show two configurations: It becomes Doc. 123456, Rev D and is now married to P/Ns 123456-03 and 123456-04. One way to do it on the drawing would be to have Detail A show the rectangular hole and note that it represents P/N 123456-03 and have Detail B show the D-shaped hole and note that it represents P/N 123456-04. So with one document, we can maintain a design history to support service requirements, especially if the implementation included accurate recordkeeping. Even companies that use tabulations (suffixes) often fail to change the part number. (123456-03 stays at 123456-03.) They just bump the document revision, as if a document revision controls interchangeability. (A very poor practice.) In this case, traceability is lost and the service department is embarrassed to ask the customer if they have the rectangular breaker or the round one. Service folks should know which breaker the customer has as soon as the customer tells them the serial number.
Garwood - A company makes an electrical panel (Doc. No 12345, Rev. C, married to P/N 234234, which appears nowhere on the document) that gets a circuit breaker in a rectangular hole. The breaker is discontinued by the supplier. The replacement breaker takes a D-shaped hole. Using detail views or notes or whatever method works best, the document is revised to show two configurations: It becomes Doc. 12345, Rev D and is now married to P/Ns 234234 and 414141. One way to do it on the drawing would be to have Detail A show the rectangular hole and designate it 12345-01 and have Detail B show the D-shaped hole and designate it 12345-02. But this method requires that recordkeeping (database relationships) includes a link from the document designation (suffix included) to the part number, including the dates where this match is 'effective'. (The document revision might give a clue to help establish traceability, but that would not be a proper way to handle it.) So with one document, we can maintain a design history to support service requirements, but only if the implementation included accurate recordkeeping.
I'll guess that most companies that have their act together use the Watts approach properly. But don't give up on the Garwood approach until you understand it well, because there is the opportunity for lean bills of materials and other efficiencies that can really please folks downstream of the design group. Operations folk will probably vote for Watts (because it is a mature and well-known methodology) when it is entirely possible that Garwood would serve them better.
Peter Truitt
Minnesota
RE: Can someone explain to me the tab suffix for a part number
1) You have an automobile airbag cover for a unique model, but it needs to be in 7 colors to match the interiors. Use the tab for color control, since all the parts made to the same drawing.
2) You have a welded assembly, with no intention of selling the pieces of that assembly. Use tab numbers for the components of the assembly to show that they are all required for the weldment. I worked for one company where we treated each component as an individual part, which allows more flexibility in part reuse.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Can someone explain to me the tab suffix for a part number
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Can someone explain to me the tab suffix for a part number
Watts would agree with example 'A', but not 'B'. I am not saying that "B' could not work, but it has a different logic that conflicts with example 'A'.
Peter Truitt
Minnesota
RE: Can someone explain to me the tab suffix for a part number
I agree that my example B may not be in aggreement with established conventions, but I have seen it. We do that where I work now. At other companies, the components were treated as just another part number, which would agree with Watts.
Company philosophy and heritage has a lot to do with existing schemes. For a new company, there are many books, techniques and standards to reference when setting things up. The company product can also influence how you may number your parts.
Someone who makes yearly changes, may want the model year in the part number for quick reference.
I saw a video of the Dallara DW12 IndyCar and they imbed RFID chips in the parts to be sure that the race teams are using legal parts. Might be extreme, but when dealing with a spec chassis rules, it does prevent unauthorized changes.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
RE: Can someone explain to me the tab suffix for a part number
Can you recommend any books that bring addition insight into configurations, document numbering, and part numbering that is not covered by Watts and Garwood?
Peter Truitt
Minnesota
RE: Can someone explain to me the tab suffix for a part number
Parts with simular geometry, that can be manufactured with common tooling, or that are 'made from' other parts (adding a hole, cutting off a tab) should be cross-referenced in both directions to each other with drawing notes to assist Purchasing in selecting vendors/reality checking pricing and to assist engineers in following revisions through affected parts/ parts families - I've seen this attempted with tabs but not successfully - the differences are usually such that a new part number makes sense.