As a rough rule of thumb, every 750 affection is worth roughly a 1% reduction in completion time on crew skill tasks.

As a rough rule of thumb, every 750 affection is worth roughly a 1% reduction in completion time on crew skill tasks.

Edit: Comments indicate that the first 450 points of companion affection are worth 2% off the top, and that further affection follows the 1%/750 formula. I haven't seen the exact data set, but this does fit the patterns I've seen closely enough to be plausible.