That's a really nice quote, suolintu. Minimalism is always best; the less stuff you put in, the less there is to screw up. That's why I'm such a fan of 'multitasking' components. Whenever possible, I try to design multiple functions into each part. For instance, if one function needs a motor and cam, and another function needs another motor and cam, I'll put the two cams on the same motor (maybe with intermediate gearing for speed differentials). It's less likely that a couple of gears will pack it up than a whole motor assembly will. There's also the weight-saving, as well as the elimination of a bunch of electrical harnessing.
As another 'for instance', if you have to pump water from point 'A' to point 'B' in a system than might get hot, it makes more sense to incorporate a cooling jacket and radiator into the water path than to add a whole external system for temperature control.
This, obviously, is not always practical, but it's a good rule-of-thumb.