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	Sat, 02 Dec 2017 10:34:12 -0800 (PST)
Date:	Sat, 2 Dec 2017 19:34:08 +0100
From:	"Nicklas Karlsson (nicklas DOT karlsson17 AT gmail DOT com) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
To:	geda-user AT delorie DOT com
Subject:	Re: [geda-user] Including parts in a BOM that are not on the board
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> This can get expensive if someone updated the PCB revision, someone
> had the old document  (.sch) with the old  PCB rev and same date and
> then order out of date boards to the tune of tens of thousands of
> dollars, based on the hidden attributes (the BOM in the schematic).

Manufacturer part number may change without changing component value. Schematic values may also change without changing value. To change footprint and layout without changing schematic may however be less common.

> 
> Always avoid having a change ripple through the design files that has
> no real impact on other files, yet must be updated.

Agree.

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