I think "bête à cornes" should stay since it's under copyright - not to be found in english-speaking areas by Google, it seems - and very much in use in France. APTE is, however, more or less adapted from Larry Miles' tools and theories to fit the French ways.

Cattle is historically the translation for bête à cornes, but I'm not dead set on it... and I don't know what cattle-head sounds like.
Copyright : I can't find the sign at the moment (how do I bring it into my answer field ?)

As in these proceedings written in English by French contributors:
"... NPD method provides several tools, adapted from the
field of Value Analysis, to help formalize the answers: one of
them is known as the "bête à corne" (APTE terminology [7])" (stephanie.buisine.free.fr/publis/ICAD06.pdf)

...Perhaps there is something similar in the Value Engineering= VA-VE (Value Analysis - Value Engineering) from Larry Miles, because APTE derives from Miles' ideas.

Under inventive-design, you'll see what the horns are for - under 7. description

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Note added at 4 hrs (2011-03-15 09:28:06 GMT)
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cattle-head diagram (known as "bête à cornes", APTE copyright)
was my answer

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Note added at 17 hrs (2011-03-15 22:52:44 GMT)
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Un clin d'oeil avec une autre "bête à cornes" http://www.laprovence.com/photo/voici-un-wasuti-surnomme-bet...