How is quality different from practicing good medicine?

So how is quality different from practicing good medicine? The author makes a distinction between medical science and the healthcare delivery system. Medical science is the best in the world and the body of knowledge is constantly growing However, the healthcare delivery system does not consistently deliver the care that physicians prescribe. It is in need of improvement. Quality improvement should be focused on those areas of medicine where there is general agreement among physicians. It should be used to improve the system, not judge the care provided by individual physicians.