I guess there are a levels of opinions on this but here's what I do.
  All photoplotted films are one part number at one revision.  Drill
file is different part number with its own revision.  Fab drawing (drill
drawing) is another part number with its own revision. The Drill file
and films are its children.
  Any part number's revision can change without changing its parent's
revision.  A bill of material is sent with the Fab drawing that shows
what revisions are to be used.  I guess instead of putting it on the
face of the drawing we use the bill of material to track revisions.
  IMHO - If you start changing parent revisions everytime you change
child revisions it will escalate all the way up.  If artwork film
changes, then bump fab, bump pcb assembly,  bump drawer that holds card,
bump rack that holds drawer, bump truck that carries rack, ad
infinitum...
George Uptain
Austin Product Center of Schlumberger Oilfield Services
(512)331-3183

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