parts list configurations on separate sheets

[lonsgsp]

We have a printed circuit board assembly being developed that has space rated components and specific notes for processing and testing a space rated board. We want to make a test board using commercial available parts (cheaper and less lead time).

Space board would be XX54321 (no dash number and deliverable to the customer), the commercial part board would be XX54321-1.

I have ASME Y14.34 and am farmiliar with using parts lists for multiple configurations of an assembly with the 2 quantity columns.

What they want to do here is to have the parts list and notes for the space rated no dash board on sheet 1 with subsequent sheets showing the pertinent details. On the last sheet they want to put the -1 configuration with its own parts list and notes. I am assuming that the no dash board would have item numbers 1 thru 60 and the -1 configuration would have item numbers 61 thru 120.

Anyone have thoughts on this or done somthing similar?

 

[CheckerHater]

I am not an expert in Configuration Management, but I see your two boards as two completely separate projects:

They are non-interchangeable; under no circumstances should they to be mistaken with each other, made from different parts using different procedures ("notes"), made in different quantities and shipped to different customers (counting yourself as a customer)

In my opinion they should be given different, distinctive part numbers and have separate BOMs. Just to be safe and make sure "internal" board never goes to space.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[drawoh]

lonsgsp,

I like to tabulate drawings. The general assumption about tabulation is that the two or more parts are almost completely identical. Any further design mods will be done to all the pieces. Concentrating everything into one drawing will save work and reduce confusion. If these assumptions are not true, you should not be tabulating.

--
JHG

 

[ctopher]

Make them separate.
Also, being for space, check with your customer that you are allowed to use it as commercial. Read the contract.

Chris, CSWA
SolidWorks 14
SolidWorks Legion

 

[3DDave]

Just wait until that space-rated board needs another component. What item number will that be?

Better to have 2 separate drawings/parts lists. This way production changes to one won't drive/delay production of the other one. Were they nearly identical variants of a single design, then the complication is worth maintaining commonality, but in this case there is no value to it.

 

[KENAT]

Not sure what's forcing this inquiry but...

If this is an in house test board can you get away with minimal drawing for the test board - e.g. bom and balooned views etc. with some note about 'refer to production part XYZ' for assembly details or similar?

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[tbuelna]

You did not define what you mean by "space-rated". Normally hardware used for space flight applications has very strict configuration control requirements. Obviously, hardware used for manned space flight needs to be tightly controlled due to the potential consequence of any failure. But hardware used for unmanned space flight vehicles/satellites also needs tight controls due to the huge financial impact resulting from failure.

If you have two pieces of hardware (one flight article using conforming materials and one development test article using non-conforming materials) that have very similar part numbers, are similar in appearance, fit the same interface, and function similar enough to pass a post installation check, then you create the potential for the non-conforming hardware to end up on the flight vehicle. There is no reason for using similar part numbers for the two pieces of hardware. With modern CAD and PDM software it is not much additional effort to make a separate drawing/BOM with a unique part no. for the development hardware. And as 3DDave noted having separate engineering documentation for the development hardware will make revisions easier and faster.

Also, you should remember that you must use conforming hardware for any qualification testing. So you might want to think some more about how the development board with non-conforming materials will be used.

Take a look at NASA-HDBK-0008 to see NASA's PDLM requirements.

 

[jassco]

Hi, lonsgsp:

I had been doing this kind of configuration for a long time. I completely agree with CheckerHater, ctopher and 3DDave. Having separate drawings is way to go. Essentially, you have two assemblies. Each of them has its own BOM. You could make them on a single tabulated drawing. But you'll face a lot of issues when you make changes.

Best regards,

Alex