Breakdown Bonus?

[Puce Moose]

I've noticed that sometimes I receive more weapon/armor parts than the description indicates when I am breaking things down. Is this a function of the science/engineering skill, or is something else affecting the chance to get extra parts?

Also, if you break things down on your ship, do you still get Parvati's +10% bonus to gain a mod? Or is it better to break things down "in the field" (outside of the ship) with her as a companion, as it mentions in her description?