ESA...who makes that final decision?

So assume that one has a disability that has involved operation/s, reasonably regular visits to the GP and is currently not working. (perhaps a picture that fits many people).

Medical assessment with ATOS gains over 15 points on the initial assessment. GP say, does not quite support the ATOS assessment. (This is completely hypothetical and most definitely not me)and I suppose that also begs a question. Do DWP always request a GP report or is it simply a request of an individuals medical record?

Anyway...15+ points in, who actually makes the decision as to work related or JSA, and if 15+ points from ATOS would an individual be put on JSA if DWP do not consider the medical history supports the ATOS assessment.

Curious.

BTD