I propose the following definition.  A "Family Tree" or a "Specification
Tree" would be a chart or list that contains the specifications and how
they relate to one another.

An example (partial!) military "PCB Specification Tree" for the 1980's
would be:
                              MIL-E-5400
                                  |
                                  |
                            MIL-STD-454, Requirement 17
                                /   \
                               /     \
                      MIL-P-55110   MIL-P-50884
                          |               | 
                          |               |
       MIL-P-13949 or MIL-S-13949  
                    MIL-G-45204
                    MIL-STD-275
                    MIL-STD-130
                    IPC-SM-840
                    IPC-TM-650
                    IPC-S-804


Current IPC Family Tree would start with bare board specs (IPC-RB-276,
IPC-RF-245, IPC-FC-250, IPC-DW-425) or with board assembly specs
(J-STD-001).

A partial example for rigid PCBs would be:
                             J-STD-001
                                 |
                                 |
                             IPC-RB-276
                                 |
                                 |
                             IPC-D-275
                             IPC-SM-840
                             J-STD-003
                             MIL-G-45204
                             IPC-L-108

Generally speaking, it's a "no-brainer" exercise.  You need to look at the
Applicable Documents section of the beginning of the spec and the specs
listed in the Applicable Documents section in the next tier of documents
until there are no more specs.  The entire tree of specs for MIL-P-55110 (I
think) numbers 100-200 specs.  The hardest thing is to know what spec to
start with -- you need to know the highest level spec.

There is a good chance that the task groups that develop these specs
already have this information (though it may not be organized in "tree"
form).  If I'm wrong about this, I may be able to assist.


At 11:10 PM 8/13/96 -0500, you wrote:
>If someone would give a definition of "Family Tree", I would certainly 
>try to help.  FYI, a complete listing of IPC standards resides on our Web 
>site.
>
>Regards
>
>__________________________________________________
>
>David W. Bergman, Technical Director
 (snip)

Regards,
David Estes
PCB/PCBA Commodity Management
Texas Instruments
ph: 214-997-2942
fax: 214-997-2188
e-mail:  [log in to unmask] (or the above address)

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